Concerning #2 that is not entirely accurate. At Legacy level 12 you can buy modifiers (do not remember exact name or type of item) from repair droid on your ship. Of course that repair droid itself already costs 1 mil, dunno what upgrades do.
All those modifiers do is improve crew skill ability (they duplicate other companions' bonuses) and they cost 100,000 credits each. Theoretically you could buy several and swap them out as desired.