"Since he committed these crimes AFTER the pardon doesn't that mean he can be charged for them?"
My guess is that he could be indicted for any crimes committed after the pardon providing the statute of limitations has not expired. If Rich is in Switzerland, this could really test any extradition treaty we have with the Swiss.
If I know the Swiss, they will not go against the will of the rest of the world if Marc is indicted for serious crimes. They will be forced to go sobbing to him and tell him the fantastic relationship they both have so enjoyed is now over. He has other places to go, believe me.