TBH, I am not even sure how the "actual" salary works in a retention.
I was presuming for a minute that we retained about 1/2 his cap, which should be $500k of actual, but since he had a bonus of $3M, don't even know how that works. Since EDM retained $750k, I think the max we could is 50% of $5.25M. Anyway, I doubt we find a taker this year, and the value of free cap space (if we got any) is only useful if you use it now or it allows you to replace short term injuries.
Considering that Valimaki may get waived for the roster spot, we actually have a decent amount of cap as it is. Without considering Valimaki, we have $2.5M minus the salary for Rozie. If we replace Valimaki with Mackey or Meloche, we gain another $500k. That includes Monahan and Pelletier. So, around $2M as it is.
If we are considering trading Hanifin or Kylington, likely the salary coming back is a wash. Trading either for a pick doesn't make a lot of sense.