There are problems with the trade system and HQ slots.

#1 Its not possible to dismiss sailors in the HQ slots or sell them from it using the Trade Menu.

#2 It a bug in that you cannot sell sailors in the HQ, but trying to sell sailors from the Harbor gets an error message about there not being enough HQ slots.

#3 its not possible to swap sailors between the HQ and harbor.

#4 Forcing players to have credits and ability points stored in the HQ slot to trade or sell is irrational. You cant use those points while in the HQ, so its comparable a 150,000 credit and ability point deposit to access to ability to trade.

I heard that alot of these problems arent as pressing using player-to-player trading.