As you've had it a week and if bought from a dealer then I'd recommend getting it back to them asap. As you are entitled to a full refund or for them to repair the vehicle FOC in the first 30 days of purchase.
Definitely must likely the fob being leant on. Alternatively if you want a peace of mind you could get a diagnostic check to see if any fault codes flag up
I'd be getting this to a garage asap, and I wouldn't be starting it up unless it's being inspected by a garage. It needs a diagnostic check to see if any fault codes flag up at the very least.
It's all personal preference from powerflow. So up to you which you choose.
You can get runner mounts which are made from the same material used in poly bushes.
Lambda sensor should just unscrew from the exhaust. Then just screw back into the new exhaust.
In theory all the 1.5 petrols fitted to the q2 or cars based on it such as the A3 or golf should fit. I'd recommend ringing your local motor factors, if it's a large one it could have one in stock.
I think ibis white might have a cream tint but could be wrong. I know my dad's 2013 A3 8v had the free colour white which had the cream tint and think it could have been ibis white.
I think the metallic white is glacier white.
There could be a lambda sensor.
Fitting the rubber mounts are fairly straightforward. It's joining all the exhaust sections together which can be the most complex to get a tight seal.
Have you looked at powerflow exhausts? My brother and a friend used them and wre happy with the exhausts.