I know the game randomly gives you quests from sets or something like that. Is there a way to just activate all of them? Maybe a mod that does it? Or an *.ini file I can tweak?

you can edit the code in devilutionx

Neither Diablo nor Hellfire, as originally shipped, offer this capability, either through the program's interface or through any configuration files. I am not aware of any mods that do so, but such a mod would be quite simple, since the game activates all quests, then picks one randomly in each set to be disabled for a given playthrough. A mod that bypassed the latter logic would do what you want.

I did it once for fun, if you don't know how to then you might be able to find it on the devilutionX chat as bday version.

We are 95% done implementing Hellfire support. You can test it by manually building, it's probably still about 2 months away I would say.

Thank you Anders. I bookmarked the releases webpage for devilutionX. I will keep checking it for updates.

It's time to check the page for updates :)

By the way you can subscribe to release notifications on github by selecting it in the "watch" drop down at the top of the page (note that it also has an option for all activities which might be a bit much as we usually do multiple small changes each day).