In order to apply for any type of visa or permit of stay based on marriage.. the Thai authorities will normally require (1) your original marriage certificate to be authenticated by the authorities in the country where you were married.. so assuming you were married in France.. this should be done in France before you travel.. or alternatively it can be done at the French Embassy in Thailand.. though the latter may be more difficult (logistically) depending on where you intend to be based in Thailand.. since an in-person visit to the Embassy is necessary.. for most people it would be easier and less costly to arrange this in their home country.. but in addition, they will also want you to produce (2) a translated copy of your marriage certificate (into the Thai language) and the translation will need to be authenticated by either the Thai Embassy in France.. or by the Ministry of Foreign Affairs here in Thailand.. if you leave everything until you get here you will quickly realise the process will be faster and less stressful if you engage an agent to handle it all.. since this removes any need for you to attend the Embassy/MoFA in person.. but the whole process could take around 1-month to complete and cost in the region of 5-6 thousand baht.. so you need to factor this delay into your application process.. which makes preparation of these documents in your home country a much better option.. assuming you have time to put arrangements in place before you travel.. speaking from personal experience of applying for a non-o (married) visa in CM last year.. but my understanding is that the requirements are the same for any application where a marriage certificate has to be included in the supporting documentation.. hope this helps your understanding.
Your reply just made me wonder whether my passport number appears on my pink card and yellow book.. so had to go and check.. and it doesn't.. so there's no need to update them after a passport renewal.. ie. after a change of passport number.. then i checked my Thai driving licenses.. and my passport number is stated on the front.. so this begs the question.. whether or not the LTO has to be advised of a change in one's passport number.. and whether revised licenses are issued as a result.. you may want to investigate this for yourself my friend.. and I'd be interested to know the answer 👍
Both documents are very useful when dealing with any Thai authority.. such as immigration, the LTO, or your local Amphur.. production will often eliminate the need for other evidentiary documentation.. but that wasn't the question that needed answering.. it related to a new passport.. and it's my belief that you only need to copy when making new applications.. meaning those authorities that may have a copy of the old passport on file don't need to be notified.. that is until you next deal with them and they request sight of your passport.. though it's best to produce both the old and new passport to evidence continuity when this occurs.. the one exception that springs to mind is your bank.. because your passport number might be recorded within their validation system.. meaning if you try to re-set your banking app (for example) it might ask for your passport number.. so it might be a good idea to ask them if they need to update your passport details or not.. especially since these things tend to occur when we are unprepared.. ie. at the most inconvenient time.. and you might not have easy access to your old passport.. so worth checking out.
Clearly this unused re-entry permit will allow you back into the country without invalidating your visa.. however you'd need to buy another one if you later decided to trip out of the country again.. ie. before your visa expires.. if you intend to travel regularly the multiple re-entry permit is a better option and should be considered when extending your visa.. it will sync with your visa expiry date and means you'll never screw up by flying without one!
Depending upon where you are travelling to.. it might be cheaper to book another flight leaving on 31 March.. or perhaps investigate switching your existing flight to one day earlier.. if the airline will allow it.
You are going about it the right way imo.. get the 60-day visa before you come.. as mentioned elsewhere you have the option to extend it by 30-days in-country.. which will give you plenty of time to apply for the 'retirement' visa in person.. your intended hotel should be good enough to satisfy the address question.. though you didn't mention whether they require evidence of a booking.. if they do then use an app like Hotels.com to book a room and select a hotel that offers payment on arrival along with free cancellation.. usually this means 'free' if cancelled before a specific future date.. so it should cost you nothing to produce evidence of accommodation.. and there are websites you can use to buy a 'temporary' booking on a flight for a nominal fee (eg. $10-$20) which is then automatically cancelled.. but you will again be able to evidence a flight since you'll have a booking confirmation.. but in tandem these 2 approaches should get you through the hurdles you've been facing.. and having gone through the process of obtaining and extending a long term visa in Thailand myself.. I'd advise you to avoid using an agent and to do it yourself.. they are an unnecessary expense imo.. if you meet the criteria you won't have any (insurmountable) problems getting your retirement visa.. you also need to be aware that using an agent could lock you in to using them repeatedly.. ie. for every future annual extension.. since you will be blind to any corners they may have cut to accelerate the process.. and this could cause you problems if trying to switch to handling the next renewal in person.. agents are generally used by people who do not fully meet the criteria for the visa they want.. said people needing someone with a 'friend' in an official capacity who can smooth the process by overlooking any deficiency.. many agents have such officials on their payroll to short-cut the process for their clients.. and if you are in this category you can argue that agents are good value.. that is provided you have the financial resource to pay them year on year to handle the renewals.. or perhaps someone has limitless resource and despite ticking every box (legitimately) they are simply too busy (or lazy) to apply themself to the task.. of course there are situations where agents may represent the best solution.. eg. such as getting marriage certificates translated and validated.. but the fees attached to these services are fairly modest by comparison.. but you need to understand the risk versus the reward of engaging them for any given task.. and you should do some research before making a decision to use one.. i wish you the best in resolving your dilemma my friend.
If your Thai motorcycle license is recognised under Uk road laws.. meaning it gives you the legal right to ride a motorcycle in the Uk without restriction.. then it would be reasonable to assume your travel insurance would be valid in the event of an accident whilst riding a motorcycle in Thailand.. however this is not the case since there is a restriction in place that limits how long you could ride in the Uk with a Thai license before being compelled to take a Uk test and obtain a Uk license.. just as there is here in Thailand.. and even if said restriction did not apply.. i would say validity of cover would also depend upon when you obtained your Thai motorcycle license.. because you would have needed to hold it at the time of buying the travel insurance for the cover to be effective.. meaning if the motorcycle license was obtained afterwards.. and is dated after the acquisition of the insurance policy.. then the insurer is unlikely to extend coverage and could deny a claim.. so it would be unwise to rely upon it in these circumstances.. when all is said and done i do wonder why you need to lean on your travel insurance in this scenario anyway.. since hire bikes should come with insurance that you can usually top up for more complete cover.. and if you own a bike it should have insurance.. it's fairly inexpensive in Thailand.. and if you are looking to ride here extensively it makes sense to be properly covered under a Thai insurance policy.. if you were ever hospitalised as a result of a motorcycle accident the last thing you want is to be denied treatment because your travel insurance is not valid!