I know that everyone just looks at it as a Kotalik dump, but in reality we dropped 6.15M off the cap during the process of that trade (Regehr 4M + Kotalik 3M for Butler 850K). That is a significant amount money that in a cap structure is incredibly valuable. As much as Feaster spoke about the acquisition of Byron, that trade was made to free up cap space to sign Tanguay and potentially Richards.
The discrepancy in cap space traded between that deal and this proposal is simply too large to make such a comparison in my mind. If you can push Holland to give up a 3rd instead of a 4th for example then of course you do so, but in such a trade we would be getting the better player, and a mid round pick. Personally I think that is enough compensation for what would be taking on an extra year of Tootoo's contract.
For Kotalik it was about the salary. You can call it a cap dump but there's no other way of looking at it but simply salary as it was possible to bury anyone you wanted to with no cap penalty. So the Flames traded Kotalik with negative value (how much can be argued) to save ~$3,000,000 of actual salary. Similarly, Primeau was traded along with a 2nd round pick to save the Flames some cash. Primeau's salary was 1.4M, but he was a capable 13th forward and the Flames needed to replace him with someone so the actual salary saved was less than 1.4M, this was at the expense of a 2nd round pick and whatever they could get back for Stralman.
Tootoo is a legitimate 4th line player, and really not terrible as a injury replacement third liner but he still has 4M on his contract. While not a perfect translation, as Tootoo would be above the depth chart of several of the Flames other 4th line/fringe players, if we look at him as replacing Jackman and another league minimum player next year the salary difference is ~2.5M, roughly double the difference between Primeau when they gave up a 2nd. Cap really shouldn't enter the equation too much, in years past you could easily get rid of it and this year the Flames have a ton of it. The biggest difference is that Detroit can't hide all of Tootoo's cap, that's a bonus for a team like the Flames.
Again how cares if he is making 8 million we aren't in need of cap space and we will most likely be below the cap this year if we trade Cammy, Stemp, Stajan etc so getting Tootoo gives us an upgrade plus gives us some cap and we get a pick it is a win - win we will never get a 2nd no need to lose out on an upgrade because we are greedy.
The owners, managements and the fans?
While the Flames have far from a static budget this year, that extra cash comes from somewhere. That's just how a business works.
The salary cap floor is 44M, the team has to spend at least 44M by the end of the season in cap, that's true. The Flames current roster, depending on the exact roster to make it out of training camp is roughly 53M. The trade deadline is ~80% through the season, by that point the Flames would have spent over 42M, they could trade all those players you listed without taking back any salary (which is impossible as even league minimum players need to replace them) and still end up over the cap. Unless Cammalleri is traded very early on in the season there's not a concern about reaching the floor. And if he is traded early, there's multiple ways of getting value to reach the floor now (retain some salary, take on a salary dump) that's a non-issue to worry about.
So, what extra value does Tootoo have over Jackman? Better player easily, doesn't help the Flames much, wont help their development and wont be the difference between playoffs. He's not putting fans in the seats. There's a chance that after paying him 3.5M he would be tradeable at the deadline in 2015, but probably should be looked at as negligible. So it works out to be roughly 2.5M for a 4th round pick, if Feaster can convince the owners to shell out an extra 2.5M I would much much rather have him do it for something than a 4th round pick. With 2.5M, that's another European scout for awhile.
And Tampa-Toronto already set the bar for a 4th round pick in the Kolzig trade. Toronto took on ~$500,000 for a 4th round pick 4 years ago. Even if there's some inflation because of the cap and profit changes, a 4th round pick isn't nearly enough to take on Tootoo unless they think he has much extra value over Jackman. Now other teams might be willing to take on Tootoo if he adds something they need, but for the Flames I would say they are looking for at least a 3rd.