Hi YagsFan - I'm happy to help!
The cost
You have to have Peacock Premium (not the free version) to watch figure skating.. It's $4.99 / month. You put in on a credit card and are billed monthly so you can cancel at any time. There's also a commercial-free version, which is $9.99 / month, but the skating broadcasts don't normally have commercials anyway.
What skating you can watch
You are right that after Skate America, NBC (or NBC Sports or whatever version shows it on TV) typically just shows a few hours (maybe 2?) of the different GPs. Peacock shows the full event - all the skaters, both SPs and FSs/FDs.
If you like commentary, unfortunately they don't usually have any. It's probably better than annoying commentary, but sometimes it would be nice to have. Typically they have commentary with Skate America (although they didn't this year), Nationals, and I think Worlds. I can't remember about 4CCs. This year for Worlds we had Mark Hanretty, which really surprised me because he's a British Eurosport commentator, and he was excellent!
You can't rewind during the live broadcast, but you can rewind and fast forward (sort of - by moving the "dot" at the bottom) when you watch the archived broadcast. Broadcasts seem to be available for at least a few months.
These are the events that will be on Peacock this season:
US Championship Series
Skate America
Skate Canada
GP Italy
NHK Trophy
Internationaux de France
Rostelecom Cup
GPF
US Nationals
Europeans
Four Continents
Worlds
Note it doesn't list the Olympics.
Devices you can watch on
I always watch on my PC; my husband uses his PC or his phone so I wasn't sure about TV. I went into my settings where they have questions/answers and found this info:
Peacock is available across a variety of devices.
Web Browsers:
Chrome 75+ (Windows/Mac)
Firefox 88+ (Windows/Mac)
MS Edge 80+ (Windows/Mac)
Safari 12+ (Mac)
Mobile and Tablet Devices:
Android: 6.0 or above
iOS: 12 or above
Connected TVs, Game Consoles and Streaming Devices:
Amazon: Peacock is supported on Fire TV and Fire Tablet devices with Fire OS 5 and above.
Android TV: Peacock is supported on a wide variety of Android TV-enabled Smart TVs, such as Sony Bravia, and set-top boxes, including NVIDIA Shield, running Android OS 5.1 and above.
Apple TV: Apple TV HD (4th Generation or above) with tvOS 13 or above
Chromecast: 1st Generation or above, including Chromecast with Google TV
LG Smart TV: LG WebOS 3.5 or above
PlayStation:
PlayStation 4
PlayStation 5
Roku:
Roku 2 (4210X model only)
Roku 3 & 4 (model 4200X or later)
Roku Streaming Stick (model 3600X or later)
Roku Express/Express+ (model 3900X or later)
Roku Premiere/Premiere+ (model 3920X or later)
Roku Ultra/Ultra LT (model 4640X or later)
Roku TV and Smart Soundbar (model 5000X or later)
Samsung Smart TV: Peacock is supported on models from 2017 or later. If you’re unsure, you can check your model number and year here.
Vizio TV: SmartCast 2.0 or 3.0 (from 2016 and newer)
Xbox:
Xbox One
Xbox Series X
Xbox Series S
Cable Provider Set Top Boxes:
Cox:
Contour Box with Voice Remote
Contour Stream Player
Xfinity:
XG1v1 (Arris)
XG1v3
XG1v4
XG2v2
XiD
Xi3
Xi5
Xi6
Flex
I hope this is helpful! Please let me know if you have any other questions. I'll be glad to try to answer them if I can.