It will obviously take a long time to get there, but TCGPCollector is essentially recommending players play the long game and not be tempted to exchange Pack Points for cheap cards they'll come across in booster packs eventually
If another replacement effect would also change the number of poison counters a player receives, such as that of Vorinclex, Monstrous Raider, the player receiving the counters chooses which one to apply first, regardless of who controls what permanents
So yes, your tokens are temporary
It could have been dropped there not from the stack at all, but, say, discarded from hand or put from the library
Aleatory is a horrible card even if you removed the chance of failure
Normally that could make the games annoying to play or very luck dependent but with this format and the large card pool, it means you need to adjust your strategy based on what you get