I would think that the 10mm steel would be thick enough for the claw, depending on the grade. I use 6mm thick tool steel, but only for the last 100mm or so due to weight, the rest is all aluminium.

Roll bars could be a good option for self righting if your bot has the right shape for it, and added protection for the actuator is good too. Mine uses cable actuated arms to self right, but I had lots of problems with them last year due to not having enough weight for the self righting system. I worked on it over the winter and this year they have been much better in the couple of fights I have had with it so far. There is more info in the build diary if you want it.