Looking at the timescales mentioned, 60 days ago and late April, i believe there is a 90 day report due before you travel. You must have the stamps moved (as Ellie mentioned in option1), before you can do that, and have registered a new TM30 against the new passport no first. Do the stamp move and then the 90 day report in one visit (2 ques).
Tod, the dates dont make sense though, 45 days before Apr 25th is more or less now, the 30 day consideration period is between application and issue, so a new extension (and rentry permit if requested) should have been issued by end of April, any May travel would be fine. So no need for reentry permit during the consideration period, just one post the approval.
no need to go to immigration. Work with the owner to set up an online account for the property, (share the login info), so that you can print out a new pdf after each entry to country, so you dont have to report to the owner each time for him to do it, or spending time at immigration. But its unlikely you will need it if your not in country for more than 90 days or not dealing with the government. But best to get a copy of the initial one.
Once you have applied for an extension of stay, the multi-entry visa is actually void. So dont leave with the intention of returning without a reentry stamp. Once you get the extension, you can add either a multi or single reentry stamp at imigration. The multi allows you to freely exit and return as many times as you like, and stay as long as you like within the year, there is no 90 day limit. (Its not quite a year if you go for another extension towards the end of the 2nd year, as again the reentry stamp becomes void at point of applying for next extension).
officially you dont need an IDP or translation as your license is already in English. However some local DLT's do seem to insist on the IDP as its easier to work with and is an international standard
understand what your saying. But i believe the starting point is that you would owe tax on the 65k you bring in for the last 10 years, and you would have to prove with supporting documentation for those 10 years that you have already payed tax in your home country and there is a DTA in place so reducing or negating the tax obligation.
except its better to fill one in, as technically anyone who has stayed over 180 days is subject to a tax audit, and with a tax return this is limited to a 5 year period, where as its 10 years without one. (Not a new rule). Not that i've seen anyone mention being audited. But you also need 3 consecutive returns if you ever want to go down the permanent residence route. But yes 99% of retirees will never have looked into their tax obligations.
you tell the government via the yearly tax return of all remitted monies, and you supply details of home country tax payments to reduce/negate any payments to Thailand tax office. This has always been the case, just that from now on you cant get tax credit for untaxed income earnt out of country post