I'd look really hard at a Shimano Baitrunner 4000D. It will do just about everything you need it to. Put it on a 6-10kg rod and spool it with 20lb braid, go nuts. Just make sure you rinse it really well after each trip and service it regularly; kayak fishing is hard on reels.
In fact I'd get 2, spool one with 20lb mono for straylining and the other with braid for ledger rigs and maybe even a bit of softbaiting or slowjigging.
Gear ratios only really really important for jigging or topwater lures, as mentioned. Outside of that it's more personal preference.
Bearing count is a funny one. I'd rather have a really nicely made brass bushing than a crap quality ball bearing, especially in a kayak. Some manufacturers find ways to pump the bearing count ridiculously high, for example putting 2 on the handle knob's shaft, 2 in the line roller, etc etc... I've seen baitcasters with double paddle handles where there were 4 tiny cheap bearings in the handles alone.
Rod-wise... I'd pick up at least one Shimano Vortex inshore jig 6-10kg, crazy value, feels like a much more expensive rod. The Nanomatrix rods mentioned above are also exceptional value but may be a little fragile on a kayak, especially if a fish takes off under the yak when it's on the surface.