get a bank account with Bangkok Bank, and do a SWIFT transfer bringing it all in at once. Then you have the FET when you want to take it out of Thailand. Then with it here Bangkok Bank has some good low risk mutual fund options to invest in.
The type of visa you have makes no difference for insurance. What makes the difference is your driver's license. After being in Thailand for more than 90 days you must have a Thai driver's license. The type of visa extension you have only makes a difference when you renew the licenses, as you need a long term visa to get the five year license. On any tourist visa you get another two year temporary license.
Do you have at least the equivalent of bt500,000 in your bank account in your name? What qualifications do you have for a remote job, as simply being trans is not a qualification. You might do better under the soft power option.
if you aren't married to a Thai you need to work, and pay income tax on wages of at least bt80,000 a month, and bt100,000 a month is recommended, as the basic requirement for applying for permanent residency, then in ten more years of working you can apply for citizenship. If you are married to a Thai after three years of working making a minimum of just bt40,000 a month you can apply for permanent residency, or directly apply for citizenship. There are other requirements, but if you don't work and pay Thai income tax nothing else matters.
there are no real issues after the first time. For all future extensions all the paperwork is the same except for new bank letters, and new pictures, unless you move, the basic same thing for retirement extension. Join the Thai Citizenship Group. They are the experts at it, and have real good documents to follow.
Something to seriously consider if you plan on staying permanently in Thailand, on a type O visa extension based on marriage you can work. On the type O visa extension based on retirement you can not work. This is a serious consideration because by working in Thailand, and making at least bt40,000 a month, married to a Thai, and paying income tax for at least three years, you meet the main requirement to apply for permanent residency, or apply directly for citizenship. You can't do this on any retirement visa type. There are other requirements, but they mean nothing if you don't work. This is something to seriously consider. With permanent residency you are done dealing with immigration, then with citizenship you can own land, plus other benefits.