You can set how intense you want glow to be in Firestorm (the Phototools floater). As for full bright... I'm afraid I don't know of a way to turn it off.

Firestorm is very slow on my system so I rarely use it. But I suppose there must be a debug setting I can find to adjust glow.

To speed things up without changing hardware, switch to Linux.

I don't know a thing about Linux. I'm on a MacBook. Will it work for me?

Feel free to laugh at me cuz that's probably a really dumb question lol

Well, Macs nowadays are (well-made) PCs, and they conform to the standards that Intel has set, so, ALTHOUGH you'll kiss your guarantee bye-bye, it'll work and it'll work fine.

But, if you know nothing about Linux, I recommend trying it out on a surrogate machine (perhaps an older, spare one) first. See which distribution (flavour) you like, etc.