I can't think of any harm in having too many frogs. As you mentioned, they are an indicator species and it's your pond and you like them, two good reasons to have them.Regarding tadpoles, Bill Cody mentioned once that due to their slow swimming and vulnerability to predation, they have a natural off-flavour and are not a large part of fish diet, although when other food sources are not plentifull, they may consider them.
My trout will readily devour any small frog that ventures out past the weedline. I would imagine that once your pond is stocked, the frog population will be reduced. In my area, anything that eats mosquitos is welcome.