For the first situation, the easiest way to do that would be to just lock in a player run the number of crunches you want with that player at PG and then unlock him and run the number of crunches you want. Groups should also work for this as well.
For the second question, there is not really a way to do this as the Cruncher is going to automatically sort your players to put the players playing last in your G/F/UTIL spots to give you the most flexibility for your late swap options.