Neovim Is a highly customizable, modal text editor program. Probably no what you’re looking for as far as terninal emulators go, but I use it daily as a near-IDE on desktop. Look into LazyVim for an easy way to get started.
I can second KDE connect–use it between my phone and Manjaro. Can’t speak to the other applications because I don’t have a use-case for many of their functions on a smart phone myself.
Don’t know if this will help assuage your fears: https://www.techradar.com/news/mullvads-no-log-policy-proven-after-police-raid
I’ve used Mullvad for years, and from what I know, they store almost nothing – only your randomly generated account number. If you are paying using an anonymous method that’s even less to go on.