im going to add about 2-3 employees to new shop, do i have to add them to the ffl or do anything different?

Not necessarily. You must not have any reason to believe that they are prohibited persons, though.

If they wil be able to manage and control firearms operations/compliance (unsupervised), then they'd need to be added as RPs on your FFL.

If you're going to allow them to transport firearms by themselves, for testing or something, it would be good (for them) to give them an employee possessor letter stating they are your employee and authorized to have them. I used to carry a binder with such a letter, copies of FFL, SOT, and any NFA forms for the shop's or customer's guns when going to test-fire them or picking up & dropping off work from other FFLs. I never had need to show that stuff, but it might save you a phone call.