I don't think that's normal. I run Synapse and Postgres, and they only take about 200mb of ram together. Load is less than 2% on a 2-core vm.

It's proprietary

I use ArchLinux BTW, because

1. It's very minimal, no bloatware
2. AUR
   ~~3. I feel superior~~
3. It just works™*

Not sure which distro you were using, but most have an autostart gui option and you would have to make some serious spelling mistakes to brick your system.

No, that wouldn't happen.

No, many people use the .ml TLD because it's free.