I'm a regional pilot. I've been at one of the largest regionals for over 18 years.
I did a career change at 27. Second best thing I ever did. We see plenty of older guys come into this career. Chances are if you've been successful in your former career you'll be successful here. It's not difficult, it just requires decent amounts of study. Realistically if you are going to do it, you should throw yourself into training fulltime. In 6 months you can have your Instructors license and then start building time. If the recovery goes smoothly there should be plenty of jobs by the time you are ready. I'm not familiar with the Aviate program, just keep in mind in a seniority based job you effectively reset every time you go to a new seat. So from Regional FO to regional CA to mainline FO to mainline CA. If you'll need the money to sustain a lifetime then you are probably looking at being junior in your seat for the rest of your career.
And this is the main crux of the question I would say. When you are junior you get crappy overnights, 4 day trips, redeyes, minimum days off, work holidays etc etc. So what is your family stage of life? Young kids at home? OK with missing Christmas and birthdays? Ability to relocate? If you are not living in base, then add the stress and time of a commute to get to the start of your trips. All that is a young mans game.....
On the other hand, if you are set financially and don't have to chase the upgrade, things can be great. I turned down my chance to go to the majors because I didn't need the money. Because I stayed at the regionals now I work 8 days a month, never do an overnight and take the trips I want. But my earnings suffered which I can afford because my wife makes good money (marrying her was the best thing I ever did).
The other option if you are making lots of money is to buy yourself a nice airplane for private flying and enjoy aviation that way. Landing a plane full of pax in a strong crosswind and heavy rain is still a thrill for me but you may find that offset by endless nights away in average hotels will take the edge of that pretty quickly.
Any specific questions, ask away. As I said, I don't really know much about Aviate except that it sounds expensive :-)