The Alltrack guys love the lift kits if you're really wanting to go that route, I'd definitely say go to a smaller rim. Me personally, my #1 mod would be an Alltrack skid plate but I'm overly cautious.
Do you mean those ridges that point towards the front of the car? I don't and I kinda wish I did, not enough to get a whole new though lol. If you do end up getting a carbon top with a indicator stripe, ask how thick they're going to make it cause I wish mine was a little thicker.
Not a GTI/R wheel, just a base Golf wheel, but I would 100% recommend it. I got mine from Vivid Racing.
I also know that someone by the name of Rogera is selling an even thicker wheel in the Interior Parts Classifieds but I can't find the link right now.
Let me just say welcome to the forums and VW ownership in general. Hope you stick around. However you've posted in Vendor Classifieds section, I believe you'd have better luck posting in the DIY Guides and Discussions.