hi Jon!
Welcome to the club! as I'm getting a new keel, I've looked into as much of this as possible, but there will be 'older hands' (some much older!) who may have more or just different experience. My thoughts are .........
1. I expected the front roller to wear. Surprisingly, when stripped, it was the12mm SS axle that wore more!
2. I'm getting new slides, front roller & rear Vee block made shortly. 'Delrin' or equivalent is needed. I don't know the cost for an increased quantity, but if your looking to buy, I can ask.
3. The 14mm lifting eyebolt should be bomb proof with the 700Lb 'small' loads we put on, but agree its cheap enough to replace.
4. I think there's several arrangements for a / the second eye to work depth gauges, hanging strops, etc, and I'm certainly replacing that, but don't know your arrangement (ours is not the same as the Parker handbook).
5. Dynema is for sure a better material. But, there's more fibres holding more water once wet. Do you want water on the winch? Ours is floor mounted, to a 5ft drain onto the winch, so Im going for 7x19 stainless if I can. There's arguments both ways, but if its steel now and you change it, I'd suggest the rollers need reprofiling to get a smooth finish for the Dynema, as the wire line will have scuffed the roller up.
Ieuan
p.s. Love to discuss this further, not least as I've tasks in the garden Julie is demanding done today, but sorry, got to go....,