Closet flange Questions for professionals or experienced DIY's

I want to understand what I see in these pictures. This is a toilet flange - drain pipe connection. There is a ragged edge on the inside of the flange. I assume this was a capped flange and this edge is the result of the cap being cut out. Am I right? Is this the typical condition of a capped flange after installation? I see PVC cement between the cut edge of the flange cap and the top edge of the drain pipe, is this to be expected? Can I safely assume I have a waterproof seal between the flange and drain pipe? I don't see any sign of leaks and the drywall below this connection has never shown any signs of water damage.

On a separate matter, the flange is attached to nothing but a piece of plywood. I pulled one screw out and it is rusted from top to bottom. The screws have been in place for 16 years. I was going to replace them, but now I'm hesitating because I'm worried that the new screws won't sufficiently "grab" into the plywood. The existing screws already penetrate completely through the plywood. Should I just leave these rusted (14x1.5 in) screws in place? Is there a glue I can use in combination with new screws?

My new toilet is here and I want to get operational ASAP.

Looks like that flange came with a knockout test plug integrated into it. Kind of a sloppy job knocking the plug out but you can see signs of the proper primer (purple stain) and the mating surfaces don't appear damaged so I wouldn't expect any leaking from the inside out. If it were me, I might replace the screws with stainless and squirt some Polyurethane construction adhesive down the holes first to help ensure the screws set tight.

I'm not sure what the consensus is on doubling up on the wax ring when the flange is recessed into the tile like that. Might be a consideration. Others will chime in - note my signature.

You don't have that toilet set yet?

Just take a knife and clean up the edges a bit.
Double wax it, drop the bowl, snug the bolts, and use clear poly seam seal to caulk the bowl.

I agree with Terry, but, assuming you are working on your own house, I would wait a few days to caulk the base. This will let you check for moisture and be sure the wax isn't leaking. You don't want to trap moisture under the toilet with caulking. A plumber doesn't have this option, he wants to get in and get out, and nobody wants to pay for a special trip to caulk. They also have experience that greatly reduces the chance of a problem.

As long as you are pulling out the crews it wouldn't dol any harm to pick up a flange spacer ring and install it.
They come in varying thicknesses or, as stacked ones that can build up the flange to the right height.
For screws use #12 stainless steel or, brass screws long enough to grip in all the layers of flooring and subflooring.



You can use wax to seal between the flange and the ring or, if you get the wax cleaned of really good silicone rtv.
You can use silicone rtv between the new spacers to seal.