Agriculture, Falling Meteors, Galacticraft, Grimiore of Gaia, Minegicka 2, MFFS, Pams HarvestCraft, and Sync are the only problems I can see with it. Though it kind of seems like you are going for a mesh of mods and claiming it's a PVP-based pack, so I don't really see the point.
Agriculture - not necessary in a pvp scenario, more foods? Well Fed? Meh, you should be more focused on fighting, and as soon as you get a pig farm + DC stuff you don't ever need to eat manually again (Baconater)
Falling Meteors - Why?
Galacticraft - When will you want to do PVP in space? It'd be a pain, I mean sure, GC is a really fun mod, but it's really impractical for anything productive. And productivity shouldn't even be the goal of a playthrough, it should be getting the strongest armor and weapons.
Grimiore of Gaia - All the mobs are OP and all players will constantly be dying; they won't have time to actually play the game because they will constantly be looking for their items. This is even more prominent if natural regen is turned off.
Minegicka 2 - It's just a messy mod with not a whole lot of purpose.
MFFS - Get a cube and a solar panel, no one can touch you. >win
Pams - See Agriculture
Sync - Very exploitable in a PVP situation.
I was surprised to not see Balkons Weapons make it to the pack as well.
UHS2 does not do anywhere near what we want. It doesn't have any Tech or Magic mods in.
Actually yes. UHS2 includes Thaumcraft, and actually a ton of the items are based around Thaumcraft as well as Tinkers (Wyld customized the pack and recipes to an insane extent to make it exactly as he wanted using MineTweaker). It also includes Tinkers construct and Railcraft, which are both considered tech mods.
Problem, after reviewing this you have Infernal Mobs, last time I checked he would only let you use any of his mods in your modpack IF one of the mods was of your creation...
ATLauncher allows for mods without permission by forcing you to download it manually.