Hi Vince,
Regarding #1, there are some options in the Operations & Warnings window. You can opt to not have the plane reset to the runway on a crash, but it will not "ignore" the crash. Warning lights, etc will still go off but I believe you can still taxi around. UNcheck the box "reset on hard crash" to change this behavior (I think it is enabled by default).
For #2, I do not know of a way to alter the effects of wheels, wake, etc, and we do not recommend it. Are you trying to develop a plugin for the sim?