Sorry I haven't been able to contribute much to this site recently, I'm still about, but I'm trying to finish the building of three new aviaries. It's taking a long time to complete as I'm trying to design them with easy cleaning in mind, so most things are being made to be removed. Plus each aviary will have a window view. With the hot weather in the UK some of my chippies are already sunbathing. Billy spent a couple of hours yesterday morning lying in the window baking him self in the full glare of the sun. I've noticed the wild squirrels you see in the park to a similar thing, sprawled out along a branch, nice life.
Anyway, I've always given my chipmunks apples, and can only find ones with pips in if they are organic. I cut apples in to quarters, and mine go straight for the pips. So I think it is OK for them to have pips over a long period of time, but they still only get one apple between the lot of them every three or four days. I did read somewhere not to give them the stones from peaches and nectarines, they are supposed to contain toxins. I agree with you about things in moderation, nearly all the foods I give mine are rotated, with certain things off the menu for a week or so. The only food I have provided every day is sweetcorn and grapes. Their supa chipmunk mix is available to them all the time, the bowls are only cleaned a refilled every few days. Otherwise I find the chippies will pick out all their favorites and leave the rest.
All the best for now, should have the aviaries finished in the next two weeks.