Hireling questions

So I just recently started playing. I’ve already ascended and I’ve just aquired myself a hireling and I have a few questions regarding them.

  1. I’ve heard on another thread that the dealer perk is the only ascension perk that works on hirelings, is this true?

  2. Is it possible to switch with the hireling? What I mean is if you main as a wizard, and have a warrior hireling, could the warrior become the main and the wizard the hireling?

3.How many hirelings can be used in a dungeon?

Any help would be greatly appreciated! Thanks in advance.

  1. Only Dealer perk will work at hireling
  2. Yes
  3. only 1 herling