Heck, I'm not near as fluent with the game mechanics as some and if something isn't behaving as I expect it to, I quit the game and reload the save "just in case" it is the type of bug you point out. Sometimes it still doesn't work (because my expectation was wrong); sometimes it fixes it (because I was right).
The point is, the game has trained me to do this because of its bugs and opaque/dishonest UI.
There's a big difference between a reset and a reload. It doesn't sound like you are undoing events, rather, you are simply resetting the game state. Ironman mode is NOT a one setting mode, it is a one save mode, so resetting the game state does not violate the clearly stated rules. However justifiable it is to do so, resetting to offset a regency or undo a misclick because of popup spam DOES violate the plain English of ironman mode. There is a difference.
Personally, I will reload a regency but not a bad monarch/heir RNG stat roll. I will reload a bad enough misclick and forgotten attrition-sunk ships, but not a bad decision or a lost naval battle. If I played ironman mode, I would still do these things... and call myself an exploiter, because they very clearly violate the stated and specific limitation intent of ironman mode.
Exploiting alliances as a smaller nation (suuuuure, Poland IRL would totally send their entire army to conquer the Balkans for Byzantium after getting their asses wooped by the Ottomans in the previous crusade), blockading straights with navies because the AI is stupid, closing the game process through the task manager when you fuck up in ironman mode, using larger nations to fight wars for you when they have nothing to gain from it, using rebellions targeted against your state to your favor, vassal feeding, migrating to other continents when you barely have a hold over your colony (yes I know portugal did it during the napoleonic wars, but that was different), etc.
I know most people do these things in non-ironman games and I usually have no problem with it as I also do them myself, but when you do it and then brag to your friends/forum members about how great you are because you exploited the mechanics of a imperfect game then I just feel sad for you...
Slow down there buddy!
Large nations could and did support other nations. Poland supporting a weak friendly state against a powerful hostile one is completely sensible. A great many great powers, especially come the latter half of the game, propped up smaller powers to offset rivals. Blockading straits or otherwise using navies to deter an enemy was also normal and historical, in fact, things like a land route from Spain/Austria to the low countries was a big deal in the Dutch revolts, and the idea of blocking the Aegean and straits was quite sound; the Ottomans rapidly conquered them in Europe after being at bay for a long time due to getting just a small fortified foothold a century before game start. Large nations did fight wars for no good reason except their sense of honor and prestige, just not to the absurd game level. Rebellions were frequently manipulated or directed, even at times by the leaders they were against, because any good leader will always try to move things in a favorable direction. Vassal feeding was the European modus operandi for the first half of the game. Conquer land, give to family, or claim throne, or elevate relative, etc. Until the rise of nation states, Europe at least was basically following CK2 mechanics moreso than EU4 for the first third to half or so of the timeframe. Moving capitals happened all the time, the only absurdity to migration is the lack of good pop mechanics making the new world a bit OP.
All you really have a point on is ironman crashing. That's an exploit.
What's really sad though is getting "tired of" other people bragging about single player accomplishments that have no bearing on your play. Who cares? I exploit the game. I do it basically every game I play. So what?