Where indexing and searching mails is concerned, notmuch is the best I’ve seen. Do note that this is not an e-mail client, it only indexes, tags and searches (following the “UNIX philosophy” of doing one job well).
I personally use it with neomutt as a mail user agent, which is almost certainly not what you want. Notmuch supports other clients but they’re all pretty arcane.
So this is not a recommendation, just a glimpse into advanced e-mail setups I guess.
I’m super happy with the ThinkPad T-Series. Solid build quality, and the keyboard is magnitudes better than the MBP i had before.
No need for external programs:
for_window [class="^.*"] inhibit_idle fullscreen
for_window [app_id="^.*"] inhibit_idle fullscreen
It really depends on your approach to learning things. If you’re looking for a systematic approach, I really like No Starch Press books for that sort of thing: How Linux Works or Your Linux Toolbox (for a more playful approach).
But in the end there’s really no substitute for installing Debian on bare metal and tinkering with it. I would really recommend Debian, because it’s the archetype of how Linux systems have been working for the last 30 years or so. Arguably, this is currently changing, but come to grips with Debian before you dabble in more modern approaches to system management.
You don’t. Even if you’re happy to support the developers of the software you use (which is great!), I think it makes more sense to download and give it the spin first, then donate later.