For Cadia, the limit for VC's was 5 iirc, and came with 1RR as standard (50pts).
Using the proposed rules, you could just us the VC;s to get the Ld bonus and save on taking RR's. The limit of 5 seems OK. In fact just been looking at the 13th BC list and there's NO limit for Lords!
As for the proposed Commanders, I'm more in favour of: 50pts +1 Ld (Max 9)
100 +2 Ld
Gets rid of any chance of having a ship with Ld 9 getting a Ld8 commander! The VC is fine by me tho.
As for the Dauntless, why not just add an option for +1 turret (+10 pts)?