ok, so i know the Aerlan already have a race specific mission chain, but i propose the professions in the game each have a specific mission chain, and a reward of a profession specific module. For example
Spy - new cloaking tech
Physicist - new shield tech
merchant - new energy module (cause they need to get around to different trading posts
explorer - new scanner
builder - new defences (so they can get out of harms way to repair)
fixer - new hull
biologist - new weapon (biological warfare

)
excavator - new weapon (sonic blaster to uncover new artifacts miles below the planets surface)
miner - new weapon (for cutting holes deep into the planets surface from space)
hacker - new cloak
raider - new weapon (cause raiders are beasts)
Above is just my suggestion. It looks like at the high levels the only difference between ships is how many crew you put into each catagory. This system will make PvP a bit more fun because now your profession will really mean something other than a small passive bonus. The module will not count as an existing cannon or thruster or whatever, but will be a standalone module. One of these modules will be able to be installed and MAYBE scale to the players level every 50 levels.
A different way to do this would be to unlock a new profession mission every x-amount of levels that would be a Mk II, III, etc to whatever previous module was installed. However, only one profession specific module would be able to be equiped.
For ppl thinking of using Glavis Devices, if you change your profession then you will recieve a message similar to what you recieve when you conquer a planet with tech you havent researched. effect: NONE. the mission will be able to be repeatabel if you change your profession, but any module gained from a previous profession will be unusable.