Immigration are checking for serial overstayers, from what you have stated on here they wont be worried about you, just in case you get questioned have a prepared Itinerary you can show them. I have been coming and going for 50 yrs occasionally I get asked. I use the Tripit app, and just show the my projected trip details. Good luck
They will only allow you to have the app on one phone at a time, we upgraded our phones and we had to go to the bank and get them to authorise the app on the new phone by entering the imie number of the phone
Apply for a qantas premier credit card, with $6000 limit (thats that smallest amount) It includes Travel insurance, also Macquarie Platinum. As long as you pay for your tickets on the card you have Insurance.
I have an app called Tripit, in that I build a proposed Itinerary of my trips. I get discounted tickets and also use points, so what I do is put in the flight details of the flight I would like to be on, and if asked open the app and show that, I also add hotels, train and bus details as well. I also add legitimate stuff as well. As others say your first airline will be your hardest, but on more than one occasion I have just opened the app and shown them as well, Again at BKK airports I have never been asked for onward bookings
I have driven in with my son who has lived in BKK for 20 yrs, he travels twice a year and even he gets caught, if you have Thai Baht, they say no, need USD. If you have USD they say no need Thai baht. It's mainly customs dept and Immigration officers. Also make sure you $USD are new notes, there are millions in counterfeit floating around and even some shopping places will try to palm them off on you in change. Nice place but totally corrupt
You can get a evisa for Cambodia but make sure you have a colour print out as well, as customs will scam you, make sure your car has all its papers as well, don't cross into Cambodia at Poipet, they will try to scam you even though you have a visa, make sure they stamp you in and check the date.
Without knowing your partner or relationship with her, how long etc. I would utilise the 60day visa exempt and 30 day extension at least twice by which time you will have worked out all the shortcuts. I offer this after 52 years of marriage, where I have seen very successful relationships and many painful (and costly) breakups. There are so many customs and practices that can totally confound westerners, and you need to be aware off before you commit
Did one in Bangkok a few months ago, and when I was sitting there getting my photo taken, there was an agent next to me with 20 Chinese passports as the immi boss processed each one, the agent would hold an A4 photo of the passport holder in front of his face. Makes a farce of the system really