For the first year of Fallout 4 I am only going to do some light modding. I would like to avoid messing with NMM at all (as my copy of Skyrim is finally modded how I want it. I would like to leave NMM alone. I can just manually install the esp files correct? Like right now I'm looking at a Piper replacer that only comes with an ESP file. In Skyrim I could manually install it then just activate the esp in the launcher.

Any opinions are appreciated!

Yes, but you need to manually deal with the load order file and write protect it because the Beth launcher does not allow modding yet, which is why it's better to use NMM right now.

Thanks

I use two different installations of NMM. They are named differently and use completely different directories. Works well for me.