My personal (extremely small) instance with only a few users currently costs around $8 / month on a VPS. Still have plenty of headroom for more users as well I believe.

I was up and running in about 5 minutes with Lemmy Easy Deploy. I can’t recommend it enough.

You should be able to set the swipe options for the default mail app in the Settings menu.

It works well on my iPad, but I can't speak for Android tablets.

It's impossible to keep up with Google's various services. Unless it's Gmail or Photos, it'll probably get killed within a year.