Bill, you make a good point that at some level the pike may feed on smaller LMB. I probably would not let the pike get to 30"+ (they are plenty tasty). I think the pike will probably eat the panfish at a bigger size than the bass and may provide better control. With proper cover the bass will not be as available to predation as the panfish. I don't think this is an either/or consideration and I like the idea of hooking into a running, thrashing, water-wolf every now and again (just my $0.02).
About the pellet trained perch. We have seen much better training success over the years. I'm sure some of it is due to better diets and techniques. I suspect (but haven't proven) that some of the success is due to genetic predisposition. If you don't eat the food I am giving you, you starve and don't get to reproduce for the next generation. I think that having a subpopulation of trained fish will help to train the others.
While perch are minnow eaters (they're opportunists like everyone else) they would prefer to make a living eating bugs and its hard to provide enough bugs for everyone. We have seen many ponds over the years with incidental populations of minnows but the perch are only interested in eating the pellets.
I use dry floating feed to train (Silver Cup or Aquamax) but the real secret is freeze-dried krill. For the first few weeks of training the fish get about 10% krill powder mixed in with the feed and the results are excellent. I start training when the perch are 18-20mm (3/4") using a number 2 crumble and once the are eating well I go to a 1mm pellet, I really like the Silver Cup steel head diet (nice round oily pellet).
Using millows to thin-out the piciverous perch is a great idea!

Jim