I'm an insurance agent. Rating is fairly complicated and you could never tell if making a claim will raise rates by a specific amount. Each company rates policies using a number of different criteria. If 1 claim regardless of amount places you in a different rating tier then it is possible for your rates to significantly rise. However, some companies may look at amount and not re-tier you in their system, hence, no rate change. You could always ask them to quote you with a new policy, 1 accident free and the second with an accident. This would give you an idea about how much the rate could be subject to change.
When you drive someone else's car, their insurance is primary and yours is secondary. If you drive someone else's car that does not have insurance then your policy would come into play. He would have to make the claim himself on his own insurance as he is the one with an insurable interest on his bike.
This is subject to the insurance regulations of the state of Texas. If another state gives primary coverage to the driver of the car, that is beyond my knowledge. We do write coverage in other states but I have never heard of the drivers insurance being primary when driving another car.