Hey so, I looked through all this code.
...It's bad. Like, it functions for the most part, but this is not a feasible engine.
I understand using Drag N' Drop for a beginning, but the problem is that everything is very disorganized here. There are a lot of instances where you use many more objects than necessary as well (do you really need 5 separate objects for a battle transition?). I also noticed that in your test rooms, there are some many areas where collision just fails and you can break the game (slope collisions just don't exist). You can also just lock your player by holding more than one arrow key at once, which is a simple else statement fix.
There are some things you should use code for because a player will not need to mess with that code. Movement and collision is one of them. The only thing that would really be in their favor to change is move speed, which is a variable you could set in the Create event.
Also, use more than one texture page. If you want this to be a feasible engine, you're going to need to teach the person using it to use more than one texture page so there aren't huge memory spikes later down the line.
Personally, even if I didn't have the coding knowledge I did, I would not use this to make a UT fangame because I wouldn't be able to get my way through everything. I do applaud you though in organizing the folders at least. But... yeah, it's not very good otherwise. It's a good start, and I know that it's the PreAlpha, so I hope that things will turn out a little better as development goes on.
Last thing; on a personal note I suggestion switching to 60 FPS before it's too late. It'll make things look much cleaner.