Isn't it a problem that once you start with an agent, you basically have to forever use an agent since you will have problems if you do it on your own in the future after having used an agent previously?
Is there any requirement on the length of the rental/lease contract you need to show immigration? Is it at least 90 days for the initial 90 day Non-O and at least 1 year for the annual extension thereafter or the length does not really matter?
Not 100%, but 99.9% if you have all the necessary documents and have not done anything illegal. Some immigration offices require a TM.30 which you might or might not have depending on where you are currently staying
I just checked this with a trial booking from Bangkok to Kuala Lumpur and the Thai Airways website wants 330 THB for holding the reservation for 48 hours. Are you sure this still works free of charge?
Isn't it that for the initial 90 day non-O visa preceeding the 1 year extension normally there is no seasoning requirement, so you have plenty of time to open your bank account during this time and have everything ready in seasoned funds when doing the 1 year non-O extension at the end of these 90 days?