When you disable your mentioned stuff, nothing bad happen. Discord is nice to me and serves me good. Just my humble opinion about this topic.
I don't know if this is now fixed, but a few years ago disabling these settings did not turn of the collection of the data. The data was still collected and sent to the server, with the promise that the data won't be used. And I don't trust that, because the founder of discord, Citron, which in previous products where found to have illegally collected and sold user data and had multiple lawsuits, the biggest one a class action lawsuit where they had to pay out over 100 million USD in damages. And isn't it a coincidence that the EULA for discord now has the user forfeit their rights to participate in a class action lawsuit against discord? What a coincidence.
I don't trust the promise of a company that has a history illegally selling personal data and lying about it, to not sell personal data. I don't trust anyone whose already known for lying.
Second you can only disable some of those things. So from my example above, that all you type will be sent to the server, regardless if you actually send that message or not, is not possible to deactivate. And as I said, there have been reported cases where people typed in a (not so nice) message but never sent it, and still where punished by moderators for it, so these messages are not just recorded, but also shown to some human moderators.
So if you have something sensetive like your bank details in your clipboard, and paste it, because you think you copied something different, well there is a good chance, even if you never sent it to anyone, that someone can see it and might abuse it.
There are alternatives though, there are open source clients for discord that allow you to join discord servers and use the discord functionality, but do not send so much data.
And lastly, whats different to forums is, in discord you have exactly one account per forum. Sure the owner of this forum has all my data relating to that forum, but thats very specialized data. Discord is intendet to be used for a lot of different things, which allows then to profile all aspects of you, rather than something very specific.
I mean you can do with you data what you want, send all your data per email to every person on the planet if you like. I'm just saying that a product by a company that is known for illegally selling personal data, where you can't turn of the actual collection of data (just the usage on the server side), and which collects a lot of data that you cannot disable at all, is something I would be careful with.
I actually (have to) use discord myself, I have friends with whom I sometimes play online together and they don't like other solutions, but I'm only using discord for this specific thing, only start it for that and stop it right after I'm done. I'm still not comfortable with this, but it's so popular that I have to use it sometimes.