SW3 - skill tree and help needed

[Raga]

Simbal:

Medium difficulty is really okay, but I must confess that I had to hire a group of 5 mercenaries (for 50k) during mission with Alex convoy (against pirates with Butcher).
I tried three times but in the end my ships survived (and one mercenary in Puma).

The funny thing is that hard difficulty gives you less exp and less cash for missions, but gives much better loot from ships. I have currently 2 saves (I managed to reach the same point on medium and hard) and on hard difficulty I have worse ships but their modules and weapons are many times better then on medium difficulty.

Hard: All my ships have 2x 200 shields
Medium: I manged to BUY one 200 shield from station.