You're contradicting yourself. If you follow all the rules, then you should be calling rules infractions when you see them. If you're not, you're not following all the rules. (
801.01 B. Players are expected to call a violation when one has clearly occurred. Calls must be made promptly.)
I call violations when I see them. I've called foot faults, 30 seconds, 3-minutes on a lost disc, misplays, courtesy, pretty much everything in the book at one time or another, both when I was an am and now as a pro. As a TD, I've assessed dozens of scoring error penalties (including four just this past weekend) and even DQ'd a couple players.
I've also countless times taken the "unofficial warning" route when players unknowingly commit or are about to commit a violation. That's actually my preference in a lot of cases, but at some point, particularly playing Pro Open (but it should apply to pretty much any division in a sanctioned event), you have to start with the assumption that the player is aware of the rules and a friendly warning isn't enough nor necessary. To me there's a difference between being blissfully unaware that you are violating a rule and being aware of the rule but not caring/trying enough to be in compliance.