It's your car, do what you want to it.

Given you purchased an extra wheel, it sounds like you are keeping the original wheel, which IMHO is the right thing to do. A future owner may want it to put it back to stock. Same goes with shift knob and handbrake lever. I am sure you can find a used handbrake lever for much much less than a new GT3 lever if you were planning on painting one like you did with the steering wheel!
Regarding wood in a car... I am not a huge fan of it from an "accent" perspective. But otherwise I have no issues with it. Wood is an awesome material. It seems just as appropriate as steel, aluminum, plastic or some composite material. And if you want you can always go classic with a 917 style wood knob which I personally think looks great and is very functional...

1.Yes, I'm keeping the wheel. I've seen one go for 92.50 on ebay so not worth selling.
2. I like wood (ok, go ahead and chuckle) this is PLASTIC that is cracking. It's a piece of sh@@. The shift nob and brake really don't bother me [probably won't worry about it. , the steering wheel needs to feel right in your hands so I like the feel of leather (skin) not fake wood.
Richard