What you have should cover you for soft plastics and spinnerbaits.
For treble hook baits (crankbaits, top water, jerk baits, etc...), I fish a medium/medium heavy action rod with a slower tip. 6.4:1 reels are good all around ratios
For frogs and jigging heavy cover, get a heavy action rod with a fast tip.
I usually prefer my rods 7' at least. Short rods are great in tight situations (floating small rivers), but fishing from a kayak I often find the extra length gives me significantly increased casting distance on more open bodies of water (like a bar pit off of the Red River)
For finesse presentations (wacky primarily), go with a 6'-6'6" ML, fast tip spinning set up.
ETA: In your yak, 3 bass rods and spinning set-up (dual purpose for finesse bass fishing or sac-au-lait) is all you will want to deal with. Everytime I bring more than that I break a rod. That's why I recommended what I did.
Honestly, the heavier action one rarely comes with me and I end up with 2 6'6"-7' MH/Fast rods and one MH/slow rod as well as my finesse set-up. This covers everything I fish with regularly. I can flip/frog with the longer MH/Fast rod when it calls for it but usually end up with TW/crank on the slow rod, TX/dropshot rigged soft plastic on one MH/Fast rod and a spinnerbait or other soft plastic on my third rod.
This post was edited on 5/1 at 11:58 am