Two suggestions:
1. Bigger sector size option.
Yeah, I know this can be tricky to implement. I think it would be fun though.
2. After Retirement, or 'Prospector the Next Generation'
My idea is that if the player retires a new captain gets the chance to buy their old ship. Current crew members would decide if they want to retire or not. Current equip load, ship weapons and cargo could be partially or completely sold off. This would probably count as 'easy mode' but wth,