1: There is many different cables, copper and gold cable are both LV cables and the 2x gold cable is MV cable ( Can be used for LV ) and they have different EU losses ( More info --->
http://wiki.industrial-craft.net/index.php?title=Recipes_and_Resources )
2: Some machines like electric furnace or macerator need EU power ( IndustrialCraft2 mod ) other need BuildCraft power wich you get from engines. ( You cant use EU to power machines wich need BuildCraft power. )
3: The only pipe that changes ways is the iron pipe. You simply get some redstone and connect it with the pipe.
4: Bees can be found across the worlds and can be obtained through a scoop. Bee produces different materials and theres is many species to explore. ( Most of them are obtained from breeding them with other species in a bee hive ( Apiary. ) ) You need a apiary to obtain the bee product ( Makes sure you have a queen/princess and a drone to put in the apiary ) and make sure the bee likes the climate you're in ( Biome. ) etc. Snow bee wont like being in a jungle biome and so on.
5: MFFS is a mod about creating forcefields wich can be very neat ( Etc. Protecting your house from griefers?
)
I hope I covered most off it and that I didn't make to many mistakes.
Though I'm sure that people will explain more/better then me.