Turbo yak

Hello all so I have an 07 G5GT that I have bolted a stock turbo from an SS and the piping and car is tuned with HP tuners and car passed smog the day after it was tuned 2 years ago. so my first issue:
A few months back the TB failed so I got another one and doing so forgot to disconnect the battery and now the idle is around 1800 rpms and I have driven over a thousand miles and still hasnt relearned , tried to lower it with a scanner and still nothing.
My second issue is a monitor , so the car was tuned two years ago and i hadnt had a problem until taking it in to have a smog done and all my monitors are set except the CAT wont ready , I have driven over a thousand miles and it still wont relearn and tried the drive cycle> to ad the car hadnt been touched or any work or tuning done since the first day it was tuned.
The third issue is I noticed oil in my my charge pipe and around the throttle body and from what ive read it can be a seal i the turbo or blow by and it doesnt smoke or anything so im guessing its blow by?
If theres any one out there that knows theses engines well and can help my out I will come to you I just want to figure this out and be able to drive the car worry free , if you can help me or can point me to a small shop please do thanks all!