Exception to this is to deburr the edges of the cut floor only, not paint or protect. Fair enough it would be inside the newly formed plastic frame but even so. I’d want to paint that bare metal before hiding it away if I did the job myself.
Normally new tyres in the wet are a handful until the releasing agent wears off. If they aren’t good now that’s a good sign.
I think I paid about £540 for the Goodyear’s fitted all round in normal 19” flavour.