http://i.imgur.com/E74A9Pk.png
Don't just jump to EXPLOITS as your first argument, my trade rank is legit
And Elite has one of the dumbest ways of measuring how adequate someone is at an activity... Being Elite in combat doesnt mean you are good in combat... it just means you spent unnecessary amounts of time shooting at NPC's that used to Spin in place like fish in a barrel (See 2 can argue Exploits

)
Most of my Combat rank (Dangerous) came from training up replacement Crewmembers from harmless to deadly due to the dumb permadeath mechanic, pointless grind
A proper measure of combat prowess would be an
ELO or MMR rating system.
In WoW, it took only a few matches to get me into the higher rating brackets... not because I played arena for 1 bazilion hours... no, I knew how to play my class and that's what was measured
And you talk about 2 years getting x y z ships.. I've been playing since Feb 2016 and have 2 Cutters, a Vette etc... All because I know how to min max my time investment vs reward
I wont be using Multicrew regardless of the payouts, because its a bare bones implementation of the concept.. I'm just advocating on Frontiers side... they want this feature to be popular and not go the way of the DODO/CQC... so make it rewarding and worthwhile.
And you talk about Combat being the only un exploitable Rank.... Do yourself a favour... get a buddy with elite rank to hop into a SLF or even a sidewinder... then shoot him dead outside of the no fire zone of the station, let him respawn.. rinse repeat