I use both WE and WEU with its enhancer.
If you use any of the add-ins or advanced trigger commands in WEU it will not load into WE. It essentially becomes a "protected" map.
I made several maps using the WEU advanced triggers and did not have a problem playing them nor did my brother in law and nephew.
Now days I mostly use WEU and Enhancer for terraining purposes. Enhancer allows one up to 16 tile slots, it also allows one to make much higher hills and steeper cliff-like cuts into those hills.
The only "good" think about the WEU triggers was the point-remove point ones. However if you read up on Leaks and Points you can pretty much fix leaks in a gui map.
Yes Leak fixing custom script can seem hard at first, but really once you do it a couple few times it becomes second nature and "easy" to do.
Of course I would never suggest to a person new to map making to start off on their super-campaign/game with lots of special affects and "new stuff". I urge people to start off with altered melee type maps where they add to the melee script and tinker with tech trees and customize a couple spells to get the hang of how it all works.
If you do get WEU you need to read the accompanying information, for example enhancer will allow you to use cliff-based tile sets you can use them for cliffs but without using specific triggers it will not play in the game.
Add-ins/ons and advanced triggers are also going to need more trigger commands - these are pretty much covered in the Read-Me/documentation of WEU.
Recently I started going through my advanced triggered WEU maps removing and replacing advanced trigger functions so I can use it in the regular WE. That is a real pain. I already wiped out the triggers of one map due to the extensive use of advanced triggers.
WEU can be like using a drug - you can quickly become dependent upon it, then when you are ready to break the habit you find that cleaning up can be a real huge pain.