Cap strapped Tampa has no interest in one of the worst d men in the league

Im assuming Ottawa retains salary but Tampa Bay has been rumored to show interest according to different sources. But otherwise I agree that Tampa probably wont be able to fit him

Horton doesn't affect the Leafs cap situation. Zaitzev is the player you should be looking at.
Say: Zaitzev for a 5th, or a centre C level prospect

Sens would never accept Horton because he actually costs 5.3m in real $$$$. Sens fans and the NHL should hope that the Sens try to get a an acceptable NHL lineup by signing at some modest veteran UFAs.
They can afford to overpay. Maybe that will help the stem the bleeding till some of the kids are NHL ready.

Leafs trade does not work for a couple of reasons. 1. Leafs can throw Horton on LTIR next year, so it's not really worth paying draft picks to get rid of him. Second (and most important), his contract is not insured, so Melnyk would have to pay the total $3.6M he's owed next year, and Melnyk does not strike me as the type of owner who would sign off that idea.

Would something around Eriksson for Gaborik work (assuming Gaborik's contract isn't insured)? Senators get a higher cap hit and an NHL player and the Canucks free up some cap space and a roster spot.

Horton does affect the leafs cap situation. Cap space is more valuable than ltir space for multiple reasons

I think Leafs should dump Zaitzev to Ottawa, but would have to give incentive to have Ottawa take him. Probably a 2nd Rounder & Zaitzev for a low level prospect or late round pick at minimum.

It doesn't affect enough to solicit a trade then. Next year we likely won't have pbs to pay, and this year we can pay without him on ltir. After that his contract is up so we are all good

Multiple insiders have repeatedly said that there is a market to acquire zaitzev and that people online badly underestimate the value that he would return to the leafs. Basically you don't need to pay to dump zaitzev.

Remember, this is a league dominated by the same ~200 hockey men. Those hockey men signed z to that contract, you really think there is not even 1 who will give him a try for a 5th round pick, like Ottawa? They need to hit the cap floor, and so they are in as much trouble as the leafs are.
Tldr: you don't need to pay to dump zaitzev

Why did the bruins trade savard? Why did Florida trade savard? Why did Columbus trade Horton? Why did Philly trade pronger?

Well I don't know about Savard and pronger's situation, but I do know the Horton one.

Toronto had the Clarkson contract, which was slightly less for the same term as Horton. Horton had his career ending injury, and Columbus did not insure the contract so they were on the hook to pay it out, and so approached Toronto offering Horton for Clarkson figuring that they may at least be paying a player who will play for them. The Clarkson contract was also insured, and so if Clarkson had the same career ending injury (which he did a year later) Columbus wouldn't be on the hook for it. Toronto has all the money in the world, and Hortons contract does not count against the cap except for pbs, so they accepted to lose the Clarkson contract.

Was a fine piece of cap management. Worked out well for everyone.

Your comment seems to imply that you don't realize ltir is a thing. You understand that injured players don't count against the cap right?

I just know how ltir works. Cap space >ltir space. There’s a good section on cap friendly about ltir, it’s an interesting read.

The last sentence is the concern. Players on ltir do count against the cap. Ltir gives you space to replace that salary. However you can’t bank ltir space, and it creates problems with waiver transaction nightmares to get under the cap when the season starts, until you can use that ltir room

You are right that cap space is better than ltir space, and the reason is for pbs. Ltir allows you to go over the cap up to the total amount on the ltir contract, but it cannot cover performance bonuses, which mean they roll over to next year if you end the year over the cap. It is why Horton is not on ltir this year, so that we can pay our performance bonuses and not have them roll over. Next year, no one has any performance bonuses to pay, and that is the final year of the Horton contract, so it literally does not affect the leafs cap situation in any meaningful way, outside of differing paper work.

That's why Toronto does not need to move Horton. We did the same thing a few years ago now, and it takes some fanagleing and paperwork at the season start, but it means that you effectively don't have to worry about it for Toronto's cap picture.

Yeah, but for a team like Ottawa who will have plnety of options to get to the floor, why take on Zaitzev for a 5th? It help a division opponent for years to come, and Melnyk doesn't want to pay a dime more than he has to especially when there are bad contracts out there that hahve a high AAV, but low actual salary to be paid. I don't think Zaitzev is a complete scrub, but Ottawa has no interest in winning for the next couple years so acquiring roster players for future assets won't be important to them.

They do need to ice a roster, to get a player like zaitzev for that cheap an acquisition cost is a steal, hence the reasoning.

Your reasoning make sense, but Ottawa doesn't make sense. I think their roster next year will be worse than it is right now.