Yes, you can emphasize completion. Sometimes it's awkward, though, as in (3) and (4) there.
The emphasis on completion seems to conflict with the uncertainty or "make a decision" sense of some of those, like (4), which in the present would mean "If I change my job, I should first tell my boss", but with the perfective suggests something like "I've already decided to change, but I should now tell my boss before it actually happens" (confusing).