Good deal for the Sharks. There will still be another deal or transaction on the horizon to accommodate White's cap hit but this is what their blue line needs. Sending Wingels and Petrecki back down will put them at cap roughly so one more move will be needed to create wiggle room. Best case scenario is they do something to rid themselves of Wallin but realistically, we're looking at moving either Torrey Mitchell or Kent Huskins.
I think you guys are fine cap-wise; Capgeek has your available space before LTIR at around $1,000,000 so with Nitty's $2,000,000 LTIR buffer you should be able to add White without any further moves...though you'll be right up against that LTIR buffer so activating Nitty probably can't occur until the playoffs at the earliest short of waiving some other guy.