Question about Kestrel outfit

I just bought this game due to it being on sale and being a big fan of other Clancy titles, also have some friends that got the game.

We saw advirtisment for the realism mode and became interested because we're big Ghost Recon fans. The biggest draw for me though was the Kestrel outfit from Splinter Cell Conviction.

I want to get it if possible before starting the game from the beginning because its a limited time item. Problem is I find it all very confusing. What would be fastest way to achieve this goal. I've already boosted the character to 40 and leveled up the pass 3 times but I was wondering if there's a faster method so I can start the game fresh with friends and have the skin from the beginning of the playthrough?

Also wondering what the point of the Stars are and if you can spend them to level up the pass? Thanks in advance for any help!