Nobody is going to hell for believing in Calvinism/Arminianism. Nobody is going to hell for believing in Memorialism or Real Presence. You go to hell for your sin.

But when there is a large number of people who are happy to make me feel profoundly wrong for not accepting their deity, or thinking the wrong day is the day God wants us to rest, or who think plenary indulgences are or aren't a good idea, or if Jesus abolished or fulfilled the old law, or if God thinks we should kill all trans people... we have hit a different territory.

These aren't necessarily salvation issues, although some beliefs may be signs of someone being unsaved (for example thinking they can buy their way into heaven or wanting to kill trans people- both show examples of someone who hasn't been regenerated by the Holy Spirit)