1. Fewer gears. But the question is, how many gears will you actually miss?
2. I don't think that means what you think it means. It's impossible to cross chain 1X.
3. Sorta... I'm in the 15T or 17T most often. Bigger gear spacing, absolutely. More chain tension, sure-- our derailleurs are clutched.

That aside, speculation is just speculation. Unless you've ridden 1X for any appreciable amount of time, you're just making assumptions based ('round these parts) on other assumptions. But I get it-- this is Bike Forums-- where an open mind is a rare beast indeed. Folks here are usually convinced of what they like or don't like, or need or don't need, right up until the minute they change their minds.