Yes, Petersen has 2-way in his first year of the deal, but I think that's there only just in case they can't/won't trade Quick or Campbell, so he has a place to go.
Yes, exactly. It's very likely Petersen will be in Ontario to start the year. That's why the contract is what it is, and why they gave Petersen $425k guaranteed. They know he's going to be with the Reign, and they're trying to compensate him because he's going to be 25 in Oct, and no closer to a #1 job in the NHL than he was in Oct 2018.
As for the return the Kings could get, I doubt it would be any of their young forwards or forward prospects except maybe Wennberg so I would expect one of their young D-men and/or a pick to be coming back. I also don't think that they would have to send one of their 1-way goalies back, since they should be very easy to trade to some team looking for a backup.
...or Columbus could have another deal in mind with another team moving out one of their goaltenders.
There just aren't that many teams that need goalies.
If my math is right, since June 2018, 9 goalies have been traded. Budaj, Grubauer, Coreau, Mazanec, Talbot, Stolarz, Kinkaid, Reimer, and Darling. 4 of those guys were traded for each other, and Mazanec was dealt twice. Once for a 7th, and again as a throw-in. He's 28, so he's got no potential left, he's just a guy that plays hockey. Kinkaid was a rental for depth purposes at the deadline. Coreau and Budaj, same as Mazanec. Just space filling goalies that happen to play pro hockey. Grubauer was the one actual goalie traded. For much the same reason that Jones had to go in 2015; Holtby was the clear #1, Grubauer was an RFA, and the Caps were up against the cap. The goalies closest to Quick in age were Budaj, Talbot, Reimer, Darling, and Kinkaid. Only Budaj was older, and even Darling had fewer years left on his contract.
None of those goalies were traded between the end of the 2018 draft and January 3rd, 2019. Reimer/Darling, June 30th, right before the big summer moves get made. A couple minor league goalies were traded on July 1st, 2017, and then the next goalie was traded until Oct 2017.
The past isn't an exact roadmap for the future or anything, but I think we're hoping against hope about the Kings goaltending situation. Old goalies don't tend to get traded. Goalies tend to have to be traded in any trades involving goalies going the other way, simply for roster space purposes. Teams don't tend to give younger goalies away, unless they're forced by the cap. I would say those are time tested observations. There might be an exception somewhere, but generally, that's the goalie market. Quick is likely going to be here tomorrow, in Oct, in March, 12 months from now, etc.