I've recently started playing Dominion, mostly bot games, few pvps. I don't own Kass, though I've always enjoyed his playstyle on free weeks, because I rarely played mid on SR so never found the need to buy many AP mid champs.

I have around 3200IP right now and was in the process of saving up for Zed, who I had a blast with on his free week (and have had one really good Zed in one of my first Dom games). I'm wondering, though, if I should go ahead and buy Kass first just to have in on my roster because of what he's apparently capable of on Dom.

As far as generally accepted cheesecake champs I own Jayce and Teemo. Should I add Kass to that list or keep saving for Zed?

That would be rude.

Mixed Opinions tbh, if you aren't planning on spamming Him then why not, also in the competitive scenario if your team doesn't have kass then the enemy team won't be able to ban Him , making you ahving to spend a Ban on kass (good spent ban though), there's always chat bans though however soe inhoouses don't do chat bans , he can be your "i want my first win of the day "champ for all that matters but there are many others that can acomplish that role.

Wait for a free week. Kassadin is actually kind of fun to play IMO, but your mileage may vary.

If you play tournaments, the guy in your team that's first pick should have him, so that you could first pick him if needed. In normals, there is no need to play Kassadin.

Play what you find fun, really. Don't feel forced to play a champ you feel is less fun.

You can win enough games without anyone on your team playing Kass, really.

Gunna have to go with Disco hear. If you have fun playing Zed, pick him up. If you have fun playing Kass, pick him up. The caveat about picking up Kass is that you will most likely get harassed for playing him at a competent level (hell, even an incompetent level), and that might detract from your joy of playing him. The beautiful thing about IP is you keep earning it, so you can always get the other champ next.

It's important to own every broken champion if you ever do draft or tournaments, so you can pick them (or have them available to be banned against you). Otherwise, don't worry about it.

the cheesecake tier is there because it's the champions who are always banned. its sort of bad manners to play any of those champions, and all of them are slated for (or receiving/received) nerfs.
Play champions you enjoy, don't worry about the cheesecakes.