First and foremost, are the bases commutable? DTW is the most junior right now for captains, but you may also be able to hold STL, ORD, or RDU with a few months or less. DEN would be longer, I don't know how much longer.
GoJet allows you to change bases every month, so you should get whatever choice quickly.
Next, the DEC course is fairly demanding. You will need to be able to fly the jet, obviously, but you are also changing and adapting to new procedures as well as being responsible for all the knowledge in the manuals. Aircraft,SOPs, maintenance procedures, cold weather ops, on board delay etc. The program is challenging but not impossible as long as you have good study habits.
The instructors Ive dealt with are all very knowledgeable and they want to see you succeed, if you have the proper attitude.
If you feel confident you can commute and can succeed then it is not a bad move. You will receive full captain pay in training and I've yet to have a pay issue. As a reserve captain at GoJet you will be flying, bear in mind you can be used to fly right seat while on reserve. Other DECs Ive spoken with tell me this is a rare occurrence. Something like 50hrs over 6 months. However you will still be paid as a captain for that flying, and personally I would much rather fly in the right seat than spend 8 hours sitting around a crew room on airport reserve like you will experience at a wholly owned.
PIC time will help your resume but it's not as much of an issue anymore, unless you want to go to southwest.
Training failures will hurt your resume but they aren't the career killer they used to be.
As far as the alter ego stuff. Most pilots don't care and the ones that do aren't doing the hiring. Do you really think the HR people at DL, UA, or AA have any idea who GoJet is or what may have happened 15 years ago?

Caveat to all of this; Taking career advice from a pilot is a terrible idea.