Leveled to 30 on Crucible...

just started on Crucible, leveled to 30 and then decided to start the campaign, is there anyway to make it at least a little challenging?

Maybe try the Veteran setting, but frankly you’ve probably overlevelled yourself in the Crucible. That’s the penalty you pay for starting in the add on.

can I do the campaign with one of the mod packs that scale the monsters or do I have to keep them seperate

You need a new character for something like Grimarillion. Don’t know about the other mods, but I would guess so. See what the mod you’re thinking of using says.

You can use GDstash to move your character to a moded game save file

Or you can wait for the expansion to release and use the tokens to move your character into elite or ultimate.
Basically I will play crucibile to aboot level 15, then go straight to ultimate. Can’t wait for the expansion.
Alot of my characters files get bugged since I use defiler alot to skip standard and elite, and constantly changing sex and classes