Toe in / out can easily be adjusted on the tie-rod.
Once a banjo housing / solid live axle housing has been bent, it is next to impossible to get it 100% true again - metal stretches. They might be able to get it pretty close but it will never be perfect. Only trial will tell if it's going to be OK and not run bearings or seals.
Castor and camber are set values on the SFA and besides modification, offset knuckle cone bearing or shim adjustment, these are only altered through rugged use / abuse. I would wonder why yours is out of spec.
Castor can change a little as a result of after market suspension fitment or collapsing spring pedestals (AKA spring perches). The topic of rectifying the pedestals has been discussed a few times here and is not a difficult thing to do. If you have this problem and want to straighten them out again, I would suggest reinforcing them as well at the same time. For castor, rather than rebuild the axle if it's not necessary, one can shim the pedestal and although it works fairly well, this is not ideal.
WRT the above said, if the camber is out of spec (IIRC it's tolerant to 1° off 90° on the negative side and 1½° off 90° on the positive), then the cone bearings in the knuckle can be replaced with offsets that rectify the incorrect camber. I don't know if these are commercially available or if you have to have them made up by a competent engineering works.
Having said all that, it reverts back to what the cause of it all is - if it is indeed a bent axle then much of that will come back into spec after the "straightening". The shop that you've taken it to sounds like they know what they're doing, so I would let them have a look at it first and advise you accordingly before doing anything.
