Would using Arwen_Reduced_XP, which slows down leveling (see below) work well with It's Bubbly?
And the same question for Everybody Bleeds, which makes it so that enemies--and the player--can bleed to death from gunshot wounds, greatly enhancing realism, IMO.
I'd have to examine them both in fo3edit to really be sure, but based on what they do and how I'd expect someone to use the GECK to achieve them, reduced XP should have no problems, and Everybody Bleeds would have meaningful conflicts. Loading it second would probably work, though any change to weapons would be overridden, and any mod-added weapons from Bubbly or elsewhere would probably not have the bleeding mechanic. Blood loss is an element of It's Bubbly, though implemented very differently. It requires you to use a blood pack (or visit a doctor) if you have been at very low HP for too long.
Which files do I actually use?
If I have all the DLCs, do I use all of the "Bubbly-INSERT DLC NAME HERE.esp" files, or just the "Bubbly-DLC.esp"?
If I have the DLCs, do I use "Bubbly-Healing.esp" or "Bubbly-Healing-DLC.esp" or both?
There is no bubbly-dlc.esp
If you have a minibalance-dlc.esp, its from a very old version and shouldn't be used.
Otherwise use any of the named DLC bubbly plugins if you have the associated DLC.
Weapons depends on The Pitt, Broken Steel, and Point Lookout.
Weather depends on Anchorage
Healing has no DLC dependencies.
Healing-DLC should be used if you are using bubbly-healing and all 5 DLCs. It basically just changes 1-2 food items per DLC to be in line with the healing module.