If I were developing that parcel from scratch, and considering some of the current investment, I would probably include re-doing the traffic a bit, taking the building where George's games is now, abandoning Main St. on that little patch that circulates that parcel and putting a garage on it. (You might be able to keep the street, but at least make it one lane and get rid of all the multiple one-way dumb traffic stupidity from the 50's that still exists there. I would reduce traffic intended for that strip by closing the on-ramp to 95S, and fixing up some of the other circulator business up by Exchange St. (potentially making Broadway two way at least up to Exchange). So have a garage on the George's spot, and a VIP surface lot across School St. from the parcel. I'd have centerfield look toward Pawtucket City Hall, and have a wharf and riverwalk along the left field side. You could use this as an opportunity to put in some weird stadium dimensions (not sure what AAA rules are on that). Maybe not mimic the monster, but having a short porch LF with some kind of terrace, etc. up there overlooking the river with the wharf and riverwalk below. The riverwalk could extend under the bridge to at least Division St. and you could have another garage on the parcel where the Yarn shop is now. Build a garage and give the yarn shop a retail location in the bottom. And then maybe they still put the hotel on the corner of Division and School. Put a pub there or something as well. Last, add a pedestrian bridge from the stadium over to Pleasant St. which would connect with that hotel and Murphy's Law which is actually a decent pub.
The bulk of cheaper parking would be at the municipal lot on Roosevelt, and probably the Slater Mill lot (on nights they aren't having events). Make the municipal lot free with a resident sticker or something, and charge everyone else if you can.
But that's a huge project that is expensive and isn't going to happen. Just dreaming.
The Providence waterfront would be tough to do unless you go down into Allens Ave and I am kind of of the opinion that that area should be industrial waterfront. With some eminent domain you might be able to do the parcel bounded by Dyer and Ship St. and connect it to the proposed waterfront parks, but there is barely enough room.