You have two options. The retool or the blowup. With the lets trade Chara, and UFAs to be like Lucic and Eriksson path there are so many variations its not even worth talking about. I do think its at least worth exploring, but lets play retool instead.
I assume that you let Campbell, Paille, Bartkowski and McQuaid walk. Iginla's money has already been spent on the Krug/Smith extensions, but you do have the 6 million freed up by letting those guys go for Hamilton and maybe Soderberg plus any amount the cap goes up. The team isn't in "cap hell" next year. More like "cap purgatory".
On the forward front, when healthy, you have a lot of depth, albeit not a collection of talent that 100% makes sense together, nor a lot of highend skill (unless Spooner/Pastrnak take another step).
Lucic Krejci Pastrnak
Marchand Bergeron Eriksson
Smith Soderberg/Spooner Connolly
Kelly Talbot Ferlin
Its also neither fast nor big. Its like team USA in old Nintendo Hockey...too many medium guys, although swapping even one of Smith, Eriksson or Kelly with a big or fast guy would make a big difference. Preferably two, and preferably Smith and Kelly.
Resigning Soderberg really depends on whether or not you deal one of those other top 9 guys, because none of those guys belong on the 4th line.
On the backend you have a real problem. You have old guys who may or may not recover in Chara and Seidenberg. Even if they do recover, and I think they at least partially will, you still are on thin ice there.
You also have a couple of young D in Hamilton and Krug who have upside, but are not ready to be "the guys", and (at least for now in Hamilton's case) clearly are more adept at the offensive/puck moving part of the game.
And then you have bottom pairing flotsam like Miller, Trotman, Morrow (has potential, though), etc.
You really need a top 3 or even top 2 guy on the backend that is in his prime, or, hopefully, even young prime to ease the transition from the Chara years to the Hamilton years and you have to give up one of the forwards to get him. The better the forward, the better the defender you get back.