As I said before, you shouldn't be modifying the actor just to achieve something that can already be done via
better methods. I never
removed your change -- there was no indication that you had modified anything so it was
never added to the resource, thus it got overwritten when I updated the main pk3 to use the latest version. You should have mentioned the change somewhere, but it (and the fact that you snuck an extra monster in there) was never mentioned.
I don't mean to play resource nazi, but conflicts like this are exactly what having a fixed monster/weapon resource was supposed to avoid. In the future, if one feels like there's absolutely something that needs to change about one of them to make something work, please ask before you do so, though feel free to make the change locally, for time constraints -- just be aware of what you're doing and make the change publicly known. If you've got a cool effect in mind that depends on it, then we'll discuss how to make it work. In this case, the Fleshspawn modification (and subsequent conflicts) could've been avoided entirely if there had been a post about the change, since someone likely would've pointed out SpawnSpot/SpawnProjectile in time for the change to be made before Gothic's time section was up.
In other news, I'm just about to check out Starscream's changes -- looks n' sounds nifty for sure!

And yeah, we'll have to make an 'exception' from the theme for the pending blue key area, I suppose, since the corrupted parts happen after it. 'Tis up to the mapper, of course. Happy to see how you've extended it.

[EDIT] New area looks n' works nice, for sure. Kudos! Nice place for a mid-boss. Still missing some connective tissue, though -- the Yellow door to the way north with the teleport still spawns copious amounts of archies instead of teleporting the player back to the start area. Another thought: If the map's not going to extend North and East of the arena, though, we'll need to place the red door carefully -- perhaps somewhere inside the future blue key area (but
not blocking the entrance like the current red bar placement suggests now, since that'd make a catch-22

). I normally wouldn't be too keen on the idea of backtracking, but it could provide a nice avenue to "corrupt" some already-seen parts of the base and get the evil flowing, so that could work.