If you like a lower angle for your paddling, then a longer shaft might help. I have a wide boat but I use a higher paddle angle and I get no hull banging although my paddle is only 210 cm . Another thing to consider is seat height. Nimbus boats don’t lend themselves to adjustment in the area but it can be done with foam. 2 cm could make a big difference. There is likely lots of knee room left under the deck, so it might be worth trying.
You can’t safely carry repair resin for composite boats on a trip without polluting everything in the boat with the smell although the vinylester resins used for Kevlar are not as smelly as the polyester resins. However, both are nasty. Also the vinylester resin has a short shelf life. Hence carry some sticky tape for that unlikely puncture or leaky crack. It is also fairly safe to carry tiny tubes of 5 minute epoxy (packaged in a sealed jar) for field repairs that will later be ground out and repaired properly. If you decide to carry spare Kevlar cloth patch material, consider how you will cut it to shape because, unlike glass fibre cloth, it requires special shears.