So I hit "skip" the majority of the time. Is this sort of behavior OK?
More than that. If you are not sure whether an edit is good and should be approved or not, "Skip" is exactly the button you should push (similarly for the other review tasks).
Usually, there are other people who will know whether it should be approved or rejected (though not all of them may agree on which).
Sure, if everybody would "skip" every not-completely-obvious decision, we would have a problem. But we would also have a problem if everybody randomly approved or rejected suggested edits.
If I don't want to approve/reject edits at all, may I simply ignore the request, or is this considered bad for the site in the long term.
You may ignore the request, if you don't feel like evaluating edit suggestions. There are many ways to contribute to the site, not everybody needs to contribute in all possible ways.
It would be bad if we didn't have enough people reviewing suggested edits, late answers etc., but for the time being, there is no immediate danger of that happening.