The imminent Chapter 7 bankruptcy, followed by liquidation, of Citadel and Clear Channel would revive this market. Each station would have to be sold off separately, and new clusters could not be created. If locally-owned companies bought each station, and each company (or individual) was not leveraged in unsustainable debt, then Providence's stations could go back to what they were. In addition, they could probably become profitable.
In addition, I would NEVER bring PPM into the Providence market.
With that said, and assuming the above fantasy became reality, here is a bit of what I would do:
PRO-FM: I would improve imaging, and make the station sound more "fun." There would be longer breaks, the jocks would talk more, and there would be far more interaction with listeners. The utterly crappy "Ralphie Radio Show" would be eliminated, and a high-energy, phone-friendly night jock would be hired.
Coast: The "Coast" brand is poison. I would go back to using the station's well-known call letters, and return 93.3 WSNE to its glory. I would make the station a full-service AC, perhaps leaning Hot AC. I also think there is a niche for Modern AC in Providence, positioned between WPRO-FM and WBRU. Such a station might sound like WBMX in Boston. Either way, the station would be live and local 24 hours a day.
WHJY: The current airstaff is actually very, very good. I would eliminate all voice-tracking, and allow the jocks (besides Paul and Al and Charles) to talk more and interact more with the listeners. I would introduce some more music variety, as they had 5-10 years ago. I would also bring back some of the things that made WHJY unique - for example, after the 4:20 Club on Fridays, the "hour of music you don't hear anymore."
WBRU: The only station I would largely leave as is.
WCTK: I have noticed some changes since the new PD came aboard. They now brand themselves as "Today's Cat Country 98.1," and they stopped using their call letters in every voiceover. I would add a bit more variety to the music. Perhaps they could sprinkle in some more gold. I would bring in a fun, CHR-like night show. I would also keep the station live and local, 24 hours a day.
WWBB: If they are unwilling to go back to Oldies - and because WHJY has the Classic Hits format covered with their AOR format - perhaps a format change is in order here.
WEEI-FM: I know this is really a Boston station, but I would definitely get rid of Mike Adams. His sports knowledge seems very limited, and his show seems limited to nonsensical non-sequitors. It is almost unbearable to listen to at times.
WWLI: Again, get rid of all of the voicetracking, and spice up the music a bit more.
WWKX: I agree with the poster who mentioned that Hot should go in the direction of WJMN. The "Hits and Hip-hop" format would work nicely in a market like Providence.