I did this a few years back. Just make sure you get to the airport early as you need to be at the front of the queue so you can get through passport control before midnight.
1/ Funds must be in your personal account with instant access. Investment funds are not normally accepted. although it can be in more than one account. 2/ You cannot apply from within Thailand 3/ I applied in the UK and it took 21 days
When you check in at a hotel they ask for your passport which they photocopy so they can register you online for the TM30. If you are in private accommodation you will probably need a printout but in a hotel immigration can see the TM30 online
Yes but you must get a certificate of residence from immigration. Banks are hard work at the moment as they try to comply with international banking rules, so you may have to go to a few branches before being accepted. Avoid Bangkok Bank.