I narrowed it down to ContractConfigurator (and ContractPacks), Cool Rockets and MP_Nazari, and TweakableEverything (Dependancy is Toadacious Tools). I took them out and it worked fine. Then I added TweakableEverything/Toadacious back in and it ran fine. Next I added MP_Nazari/CoolRockets and ContractConfigurator/ContractPacks and it failed. Then I added MP_Nazari/CoolRockets and it ran fine so obviously it was ContractConfig/Packs right? Well for some reason after adding everything else, I re-added ContractConfig/Packs back in (in order to take out the packs one at a time to figure out what was causing the crash) and... it ran. So I honestly have no idea why it worked out like that.
Maybe someone can explain this but it worked so all is well in my book
*Edit* I forgot to mention that I had crashes after the mods above were removed from USI and associated mods. I updated that and it ran, so then decided to update CC to it's latest version (which I believe was the same version however when updating one file was smaller) but it has worked since that update. I imagine it was a file that cocanates the packs for loading, and there was lingering data in that file so re-adding it from a vanilla point and having the packs update said file may have been the fix however I can't be sure because I don't remember the file's name as I clicked "copy over" too quickly...