No problem getting to the floor. Don't need any charity...

There are a lot better ways to for Sens to "get to the cap floor" as so many say, than to overpay for players. Now if Sens think those are fair deals for Ceci/Nilsson OK. But Sens don't have to overpay for anyone for "cap floor reasons".

Correct. They don't need to do Toronto a favor taking Marleau. Ceci gets a raise. Can be traded later. They need a goalie. They traded for Nilsson.

Few teams if any "need" to hit the cap floor. But some teams do have space between the cap floor and the ceiling. For instance Vegas would gladly trade LTIR Clarkson for nothing if Ottawa needed "floor" cap space though Clarkson doesn't affect Vegas's cap at all.
If Marleau was to retire, I don't see why Ottawa wouldn't take Marleau's cap hit for 6.5m.(no salary) with a 2nd round sweetener. The Leafs could trade his cap hit to another team, so why wouldn't the Sens want a free second rounder? Ottawa and Toronto are hardly playoff rivalries next year, so the Sens would really be hurting themselves by not taking the pick.

How in the world do they trade Ceci later with a $5.5M cap hit ?