He should make a stretch goal like: all the stuff I promised will be done and finished :p
With that many stretch goals I fear he'll end up delivering only an unfinished product (again).
The thing I'd probably love the most is much more ship frames to choose from. Also customization options that impact ship looks and behavior by a lot, not just cosmetic.
That'd lead a feel of a breathing universe for me - especially im among those ships could be huge giants like the reclaimer.
I don't want to go into a mining area and only see Orions. Or into a salvage area just to witness a herd of 100 Reclaimers grassing the fields for scrap metal. :D