Oh, that was really fun read. I am sure you would be allright without any tips. And youtube is full of proper helping videos anyway, but since you asked I will give you this one (since you seem to like to smuggle things for profit and fun!). When buying freighters, buy pirate versions (pirate versions, not necessirily buying from pirates themselfs) - they have special hullmod that makes illegal items not detected via inspecions most of the time. But this is small tip for somebody who likes to smuggle stuff.
Tip for how to play this game is already given by Nick XR.
Have fun out there.