The Meaning of Life, the Universe, and Everything.
I'm looking for 1-2 mods, that all they add is pipes for transferring items (compatible with most of not all item containing mods), and a power source (& preferably a pipe to transfer power as well), either in RF and EU, without the need for IC2 or TE (something like EnderIO, but only energy) (prefferably RF).
My pack has some stuff that may need the usage of RF/EU, but I don't want a big 100-mods pack, just a small with about 10-20.
Well, if you haven't ever heard of this rarely used mod called Minetweaker and its buddy Modtweaker (Sarcasm intended), you could use with EnderIO, Extra Utilities, IndustrialCraft2, Thermal Expansion, etc. alongside configs to get some pipes, power gen, and power transfer. Just remove the recipes for the other stuff, or, when the mod has it in the configs, just disable the excess items and hide them from NEI. Extra Utilities is a pretty good one, since with other mods power gen, it might require several machines, while Extra Utilities' generators use stuff available in vanilla, such as coal, food, or potions. The downside is that then you have a bunch more work to do. Big Reactors is one mod that does power gen, albeit it doesn't have power or item transfer. Let me think about it for a bit, and I'll try to think of any mods that add just item and power transfer, alongside power generation. Hope this helps!
Some other power gen mods include Deep resonance and Advanced generators. You could also do Buildcraft, downloading only individual modules, i.e. Core, Energy, and Transport. You'll probably get a little excess, but you can use Minetweaker and Modtweaker to remove and hide that excess if you want to.
No, there are no dependencies, if my memory serves me correctly. However, the core module is required for any of the other modules. Also, here is the list of modules and what they do from buildcraft's website:
Core (Dependency for all other modules; wrench, redstone engine, list, map location)