General

PC on Tree Branch Nose AND cubing and SoK questions

1. PC - Is a Tree Branch Nose worth anything? Got it in Henesys with the ticket from Hot Time. It's an untradeable face accessory with STR +5 and 10 slots. Apparently a regular SoK won't work on it and I'm not sure if a platinum SoK will either.

2. (a) I don't get the difference between a regular cube and a premium cube. What's the difference?
(b) I got epic potential with the cube from Hot Time (Hot Time woog!). If I use a regular cube, will it ever lower down back to rare? if I use a premium cube, will it ever lower down back to rare?
* regular cubes are on sale, btw. 960 NX!

3. What's the difference between a regular SoK and a Platinum SoK?

Thanks A LOT in advance!