I don't know about really needing a 4C, this season at least. I'm going on the assumption that Beagle will return to the lineup, and he's a fine 4C who wins draws and can PK. Overpaid, yes, but it' not like he can't play where we need him to. I've liked Graovac's play in the limited time he's played as well, and would like to see if he can develop in that role if Beagle's out for a bit next season.
3C, absolutely need one, and though I've seen it suggested, I'm not sure bringing Sutter back is the solution, even at league min. If we move some cap out, I'd much rather spend a portion of it on a player like Wennberg in free agency, save the rest for mid season upgrades, or if a good trade opportunity comes along for a Pesce/Cernak type D at a comparable cap hit.
As for RD, it doesn't seem like there's much value after Hamilton in free agency this year, (Larsson?) and with the hiring of Brad Shaw, I'd like to see what kind of changes he can bring to the defensive scheme before we go out and spend big on a player like Hamilton. Would also like to see what Woo can bring to the lineup as well. Parayko is also available as a UFA next offseason, when we'll have $12m in 3 players off the books, as well as the Lu recapture penalty.