If you fit wheel pants you definitely need a valve hole and an extension. With that its not a big deal to check and correct tyre pressure.
Yes the fairings are difficult to remove if you get a flat and you need to lift the wing. In my opinion the plane looks better with them on.
With my RV9 I lose 10 kts without them on. Obviously more drag at higher speed. My 12 will have first flight in next 6 weeks