Meguiars PlastX, works a treat on yellowed/blotchy 34 headlights
and as for the sticker, you can try heating it with a hair dryer or heat gun, not leaving the heat on one spot for too long, and then slowly work your way in from one corner, once you get the sticker off just use a warm damp cloth to rub the excess sticker glue off.
If need be you can clay bar anything left behind.
and welcome, PS, love the steering wheel, was considering re-trimming my stock one in a very similar way to that one, only with a more golden/tan colour where your silver is