yes, you can do it online on the e-visa website. The 90 day type O visa expires when you leave Thailand. It is continuous, not cumulative. You apply for another one the next time you plan on returning.
No doctor in Thailand will write a treatment plan without physically meeting you here in their office. You come here, get tested, then a treatment plan is agreed on, and written up. That is the only way.
Call them. You are not put on hold waiting. You are told to enter your problem, and phone number, then they call you back, usually within a few hours. This prevents large phone bills on your part.
Actual tourist numbers are up, it's just the money they are spending this time of year is down in certain areas. One in particular is the fact all tourists are drinking less alcohol, and seen in the fact they now allow alcohol sales in tourist areas during religious holidays. Beer sales alone are down almost 40%.
you're living in the past filled with rumors from long ago. With overstay there is no longer buying your way out of it, and hasn't been for over a decade.
If you are stopped for any reason by anyone in authority, and are discovered to be on overstay, even one day, and not on your way to the airport, you will be arrested, placed in immigration detention until you pay the fine, and the plane fare for your deportation, then banned from returning for five years. Overstaying is never recommended.