if you're talking about using redpower, then you are clearly either using the wrong version of minecraft, or the wrong version of redpower. there's been no updates to redpower past 1.2.5, and if you're using the latest forge you are probably running 4.1.2 (4.1.3 maybe? is that even out yet?). this leads me to believe that you are probably using the wrong versions of pretty much everything.
make sure that the mods you're using actually work for the minecraft client version you're using. this is also why EE2 doesn't work. there is no EE2 for 4.1.2 or 4.1.3, whichever is current nowadays.
edit: in fact, now that I've read the entire OP, you may want to not try and copy/paste stuff from tekkit and expect it to work.