I like Santorelli and love that, apart of the qualities we are looking for, he has good offensive upside. But I hope that the management explore other options and compare them. Like Riley Nash, as you said some time ago. He has a crazy cap hit (575K!), is younger, natural C, has even played in the 1st line of an NHL team, has good numbers this season (7G 12A) and the last one and is good in the circle (51.6%). He might be a better fit than Santo, but his value is a complete mistery for me.
Some other options I'd explore:
Trevor Lewis: personal preference, especially for his cup experience and the passion and hard work he brings. He doesn't bring a lot of points though, and given the Kings situation he won't be cheap. He has this year and another one in his contract at 1.5M of AAV. Fits perfectly in what we are looking for, a 3rd line winger that can switch to center whenever it is needed.
Brad Richardson: UFA, grit, decent secondary scoring, and I'm almost sure that he would be cheaper than Santorelli. I have never known him for his FO ability, but he might work.
Max Talbot: playoff clutch, veteran locker room guy, Colorado would trade him with any doubts, he's older, so could be have for a...4th rounder?
Also I would try to keep that pair of 2015 2nd rounder, this draft is really deep.