Why would someone use gold cables when copper ones work? I didn't make any gold cables until I realised that I needed them for something. Is this really a common mistake?
I was nervous of BC because the early engines (apart from the pitifully weak Redstone Engine) have a tendency to explode. IC2 stuff only explodes when you progress to higher tier machines and so should know what you're doing and have the resources to replace the occasional smoking hole in your base.
TE energy transportation is too easy IMO. REC just seems like a cheat item.
The REC is necessary, but maybe is too cheap. The Energy Tesseracts are a whole different steam engine.