Can I bake a turkey in a baking bag in my Rival 22Qt Roaster Oven (RO230-C)?

It depends on the size of the turkey, because the bag can't ouch the top, sides, or bottom of the roaster. But the roaster already cooks moist, so the bag may ber overkill.
The Rival manual suggested 375 for pre basted or 350 for fresh 9-14 minutes per pound. In my experience this is too hot. I use 325 for 4 to 4 3/4 hours for an 18 pound turkey. The USDA now uses 165 as the end point temp (down quite a bit from a few years ago), but if you stuff, that has to be in the middle of the stuffing, and the turkey will overcook somewhat while it gets there. All experts agree that turkeys cook better and safer if unstuffed, so considering that you will have to make an extra pan of stuffing to have it for everyone, you would be well advised to cook your turkey unstuffed and use some of the drippings to flavor the pan of stuffing while the turkey rests.