So I have a bike equipped with 2200 brifters, an 8-speed cassette and a Sora RD. The issue i have is that if I go over a particularly big bump (or if I just roll my bike down some stairs), the chain will come off the chainring. Obviously it's pretty easy to fix most of the time, but once it somehow got jammed between the chainring and the frame and it took a good 20 minutes to pry it out, which not only made me late but also took a chunk of metal out of the frame. So my questions are:

1. Would upgrading the RD do anything to solve this problem? If so, what level (tiagra, 105, etc) would provide a noticeable improvement? If not, do you have any other suggestions?

2. Is a 10-speed RD even compatible with 2200 brifters and an 8-speed cassette, or would I have to change those out as well?

3. If I were to have to change out the cassette (you can see the progression of questions), would I be able to install a 10-speed cassette on the same hub that the 8-speed one is on now?

Thanks.