Yes replacing slider with french. I'll double check, I swear there isn't much of a casing to pull away to check the RO. It's like the edge of the door/sill just inside the layer of painted drywall. No like flashing/edging like I've seen in a few video's.

Need to dig up the original paint and some other materials to repair a replacement I suppose.

For contractors, am I looking for remodel types, or not sure going about finding the right types other than what home depot provides. Lowes website is kinda ass, so been happier with what I'm finding on HD so far. Need to go in person and see what they have to demo in store etc vs just making a shopping list of the different sill pans/insulation/sealant etc I'll want if DIY.