Thunderbird definitely does have autosync nowadays. No tray icon, true, but it can send native notifications which isn’t much worse.

People have already said how to fix this, but I’ll add this different piece of advice: start using FreeTube.

If you actually read the article, this is just a normal-ish (although peer-to-peer, which is interesting) free VPN, it isn’t actually oriented towards cheating. The funniest part is that if the article is to be believed, the “cheating” consists of simply increasing your ping. Which… you don’t really need a VPN for.

It’s not much of a stupid question even given that - for a refractive medium, speed of light can change with its movement. Though for air it’ll be extremely hard to directly notice; it has n≈1.0003 so speed of light in air is already 0.9997c, and increasing it to, say, 0.9998c would require moving the air at 0.166c.