I use it to chat with one or two people. Privately, although apparently not as privately as I thought :/
It's not surprising, because most of these non-spying, non-tracking "alternatives" you find here on Steem sound too good to believe and usually are. Frankly, I'm disappointed by this...But also, they've got you by the balls, sort of...what other app/program can you use to chat that isn't intrusive?
As for slowing down the computer, I don't know. My old one was pretty...well, old, but the Discord sure didn't help and the fact it booted up automatically pissed me off something awful, so I can relate. I also didn't like that I'd be watching a movie and all of a sudden, it would start pinging in new messages even though it was supposed to be closed....So, you're not alone. And I don't think it's a tin foil hat thing, either. :)
As for your writing spot....you lucky, lucky bastard. I'd love to have that view.
I know it. This place really is a treasure.