Make sure you are removing mods from the correct location. For example, if you happen to use the Vortex Mod Launcher, it changes where mods are stored and you have to remove them from that location. You can open your log and it'll tell you what mods are being loaded near the top of it. In fact, it would be useful if you posted your log. You can find instructions for doing that in the pinned thread in General Support.
As far as the UI mods, I'll leave that to someone who knows those mods, but it could be that they are not updated to work with 1.1 EXP and even if they were updated for 1.0 (not sure if they were or not), they still might not work in 1.1 if there were changes that affect those mods. But being in experimental will not prevent you from removing a mod.