Don’t know who exactly you are interested in, here are some random known accounts:

• the EU commission (other EU institutions as well): https://ec.social-network.europa.eu/@EUCommission
• gog games: https://mastodon.world/@goggames
• The New Stack: https://hachyderm.io/@TheNewStack
• Mozilla: https://mozilla.social/@mozilla
• Rust foundation: https://social.rust-lang.org/@rust
• Free Software Foundation: https://hostux.social/@fsf
• Electronic Frontier Foundation: https://mastodon.social/@eff
• Greta Thunberg: https://mastodon.nu/@gretathunberg

Regarding individuals, I’m following a bunch of software developpers. I’m mostly interested in topics, hence I prefer Lemmy by far.

DHT is autonomous and does not require a tracker. Usually it is only used as a fallback as a regular tracker is quicker. It’s p2p, and is split accross people hosting it.

A phone server that is disconnected from cellular is already broken anyways.

I uninstalled it quickly after finding out it was trialware (missing features; popups to pay)

I’m fine with Rofi. I’ve used xfce4-appfinder also, it’s less minimal, not configurable (good graphical defaults, might be what you want).