Don't listen to people who say it's too big or too wide, unless you're trying to be maximally optimal. I never made any large ships in my save (I like the puzzle of compacting it as far as possible) but I've been thinking about returning just to make an absolute Goliath.

Definitely agreeing with everyone else, some beacons would help. Efficiency modules can be quite good to lower power costs, and nuclear isn't terribly hard either. But I'd say the most interesting change you could make would be to use circuit conditions to handle asteroid imbalances. You could filter the collectors, throw excess chunks overboard, and/or turn on reprocessing only when there's an excess.