Salary cap aside, I have no problem with Parise playing on the 4th line. Given a choice between him and Bjugstad, I choose Parise. He's probably one of the best 4th line players in the NHL....just stinks that his cap hit is what it is.
Here's the deal with the salary. If he isn't LTIR, it doesn't make any sense to buy him out. The rules for how that affects the cap are such that you are going to get a lot of room in 21-22, but virtually none in the last 3 years of his contact.
I don't understand all the details of the LTIR system, but I think that you have to be in cap compliance, or near to it, at the start of the season, before you can start using it. That could be problematic, depending on how much of his cap hit you actually use.
Here's what I mean. Let's say, just for argument, that you lose Soucy to the ED, and you end up buying out Rask for next year. You are right at the salary cap for 21-22. You like your guys, though. There is no one you want to lose from the roster for 22-23. So, you try to LTIR Parise. The only cushion you have in the cap are going to be the ELC's and Minimum guys you sign to fill the roster. There are maybe 2 forwards and a D of them, although that's a question as well. By the time you extend Greenway (and he is making a good argument that you want to keep him right now), it costs you another couple million, and you are into LTIR range.
I'm not sure how the details work there. It's complicated. But it's not as much of a 'get out of jail free' card as it looks like when you are using it in multiple seasons.