No requirement to be in home country when you apply. But do need to show that you're not in Thailand (entry stamp to other country, hotel invoice, etc).
Not going to happen unless she's from a wealthy Thai family and has business ties to Thailand and significant assets in her name. Unless you can buy her a Trump Gold Card. You might get a fiancee visa but it will take months and you so need to marry her within 6 months of her arrival.
you could investigate a remote customer service job with a USA company (phone support). But that job certainly isn't going to give you additional peace of mind.