This is the range of dates within which you can enter Thailand. You could then stay 60 days, and extend that by another 30 days at an Immigration Office. At that point you would need to leave Thailand for a period (an hour/day) and get a 60 day visa-free stamp when you come back in. You can then extend that by another 30 days, as before. Rinse and repeat, until a border official thinks you may not be a genuine tourist
Busiest days in Immigration Offices are Monday and Friday, so avoid them. And if you get there early (check opening times for the one nearest where you'll be staying) you can easily be out in a couple of hours. Take 1,900 cash, your passport and a photo
That's a huge fee. OK I gather it is bureaucratic and very detailed. But with a Thai wife to help you understand, you could do it yourself. Take your time. Get hold of the forms from your IO. Ask them a million questions about exactly what they need from you. If you get it a bit wrong at first, the worse that will happen is they'll ask you to do it again, or provide another document, or whatever. It's doable. Good luck
Thailand is doing all it can to boost tourism, and it's flagging economy. They'll deal with people who are obviously taking the p155, but seriously you will be welcomed
You have established that you are a tourist by returning home after each visit. That's fine. If you hold an appropriate passport, you could come without a visa and be stamped in for 60 days. You can then extend this for a further 30 days at the Immigration Office where you stay
1500 years ago is irrelevant to the sin sod issue and it's context is not religious at all. Today just 0.1% of the Thai population are Hindus. You need to do some more reading, this is not a subtle nuance like Protestants and Catholics