Yes if you have 12 months of international transfers of at least 65,000 baht to your account.
The transfers do need to be shown as international transfers so using a service like Wise may be problematic as some deposits may be marked as a local transfer.
It’s office specific. Some will insist on a re-filing after a stay in a hotel or hospital.
If you don’t need interaction with immigration then you don’t really need to file, but for those offices that insist on an up to date one you won’t get services without it.
You can apply for a re-entry permit but all that would do is keep your current allowed to stay date “alive”. If you won’t be returning by that date then the re-entry permit is useless.