Being in your home country for some consulates isn't a requirement - as maybe you just want to apply for your next trip, already. Traveling from your home country is, at times. But that can be "established" with some sort of travel itinerary. Once a visa is obtained, the port of entry does not matter, though.
Alternatively, you can try a get a eVisa from the Thai consulate in your home country, instead. Maybe their requirements are less intrusive and the whole process of obtaining a visa is more streamlined this way.
Like everything Thai immigration related: way over the top (and every office making up their own crap). Especially for a simple TR tourist visa. But what can you do? Make sure you blacked everything out except the periodical balances, though. Transactions are non of their freaking business.
Further to what Brandon said: Some schools will tell you that you would have to leave the country to get an ED visa from a consulate abroad. Others will try to charge you north of 10k baht baht merely for changing the visa in-country. Be cautious about both kind of schools.
In theory: no. In real life: yes. How could the Thai consulate in the US know where you are filing for the electronic visa from? Sure, they could ask for a flight to Thailand out of the US. But there are solutions to come by such proof, if needed. The visa is not bound to any specific flight or port of entry, once issued.
"Your" district is the district in which you last reported your address, I presume? So, going to another district, checking into a hotel, making sure that hotel does the TM.30 reporting should give one the necessary "proof" of current residency in that new district. I know, painful, but sometimes immigration office shopping for more reasonable procedures is the best option.
Thank you. No issues to be expected if one would really milk an METV like that? No issues with actual border bounces / stays outside of Thailand only for a few hours or days?