Installation of guides and seals can be FUBARed. It really does sound like that could be it, though.

 

Cold start and decel smoke can also be the turbo. On shut down, oil can pool in the turbo because the oil level in pan rises and covers the drain, and on decel you get increased crank case pressure due to rings not being sealed with no load.

You can loosen the manifold and pull it away from the head to see if you can see oil in the ports coming from the valve guides/seals, but I doubt that's an issues at only 60k miles and having recently replaced the seals.

 

If that really is your oil consumption, cold hard facts, then I say no problem, you are just experiencing the joy of a catless car.

 

That's not a TON of oil... but would drive me nuts, either way. I get OCD about leaks n stuff. Smoke would drive me nuts. Hopefully you track down the problem!