I have been playing these games since I was 6 years old and I remember that as my CPU updated I would need things like risingsun, dosbox, CPU killer. Will I need to redownload these or does GOG have the patches built into their downloads?

The current versions of the installers should have all of the relevant patches and set Dosbox to run at an appropriate speed to avoid crash issues. (There are still some bugs that can occur in the games regardless because they were never patched at the time, but they're relatively few, with the Domovoi issue in #4 being the only serious one.)

I'm less concerned about the Domovoi (which was mainly an user error in event sequences), and more concered with the infamous error 52, which required CPU killer. I've written 2 guides on SoD alone and that is my largest concern. I am also hoping that the chemical formulas from SoD are included and the map of Shapier is included.

I am also concerned about the error in Dragon Fire which basically makes the end of the game unattainable WITHOUT killing someone.

It's definately worth the $10, but I'll probably contact Admin about how to run the patches if need be.