Yes any standard sized utility knife blades should fit. I tested a bunch of different brands from my local hardware store.

I have a 3D printer buyer's guide on my website that lists a few. I mostly use and would recommend any Bambu printer, there's a few that can suit any price range. Elegoo also make good printers too which won't break the bank

My two are pretty good with not eating things they shouldn't so I just made sure stringy bits were cleaned up. Googling says PVA/wood glue is safer for cats but I would check brands if they are non-toxic

STL files available on Thangs

I have the STL files on Thangs for 3D printing.