Hi and thanks for sharing your mods. I have tested a few and here is some feedback. Just to be clear Im using a lot of mods and darkness falls.
Khelldon-HolyHandGrenade - cool, will make it rare drop just for fun. I reduced range and damage to avoid the whole gaming lagging a few seconds.
Khelldon-AwwNuts - it got added to recipes, but I did not get any nuts and bolts when harvesting/wrenching, conflicts?
Doughs-YouveGotMail-2.1.1 - nice mod to "pimp up some" loot containers 
, I will keep this.
Doughs-Electric-CapacitorBank-1.0.2 - I did not get this to working sadly, I saw one flash of light and then it was gone, maybe I did not understand the concept. Also I could not harvest any capacitor, I see that the capacitors get added to the blocks, but i cant harvest them.
Doughs-Buff-PipeBombs-1.0.6 - deadly business, if I have pipe bomb in my hand after casting the one I ignited, I get a lot of damage even far away.
Doughs-Buff-Sounds-Common-1.2.0 - not working for me, I think maybe conflicts with other mods, using Robeloto_LoudSoundsLowered and Reduced Hit Sounds While Crouched.
Im going to do more tests, since most vanilla blocks is not touched with any mods I afraid there can be some conflicts.