Buggered up screws and impact drivers:
My father always told me "Son, always use the right tool for the job."
Household and toolbox screwdrivers are not meant for use on firearms. You need a decent set of "Hollow Ground" drivers; mine only cost $45 and have served me well, for a professional gunsmith most will pay over $100 for a pro set.
They will fit the slot proper and, if used properly, will not bigger up the slot and keep slipping out and buggering up the barrel or whatever the screw is set into.
For 'stuck' screws; I use Choke Tube Lube and Don't Over Torque, never had need for an impact driver (or blow torch or drill).
However, I pull mine at every cleaning (aside from 'field cleaning' if out for a few days), I clean the threads and apply a fresh coat of Choke Lube, even on the nipples of my revolvers - yes it takes a few more minutes but allows me to come in with cotton swabs, pipe cleaners, small brush and clean it all out.
Even the tiny cleaning/pressure release screw that is on some percussion rifles (not all) I clean the threads with pipe cleaner and Lube the threads.
This is my way, others will protest (some even cling to their impact drivers and shout me down).
As for the claim "Constant removal will bigger up the threads"; old wives tale, just dont over tighten and when replacing do it proper, and Don't Cross Thread.
As for Liner vs Non-Liner; I have both and both fire great; if properly maintained.
Without proper maintenance and cleaning, you end up with ones like a couple that were brought me: never cleaned and heavily used - one I could not remove the nipple (Percussion rifle) so I sent him to the gunsmith: Expensive repair.
The other had one of those pressure release cleaning screws (Percussion rifle) so buggered up and froze in rock solid: sent him to the gunsmith - he said repair would cost too much so he will just "live with it".
Both where just reenactors who never shoot live balls, so...