Hey Analogue,
For starters, It’s awesome to see the amount of passion you have for an industry that you have yet to really get your feet wet in. This kind of attitude is lost in many designers and students of design and from my small amount of experience, it’s the ones like you that really come out ahead.
As you said, you wrote a pretty extensive post, so I’m going to try to bullet point my response for simplification, although I doubt mine will be any shorter.
In terms of school, If you can take the financial blow, and risk your financial, relationship, and personal securities to START a career at 30 that you will no doubt continue to love going to, start from scratch. It sounds hard, it sounds SCARY! But then again so do alot of big risks you take in your life. But if you come out of school with the same attitude you have now, all those things like portfolio, job experience, and software knowledge will come as you study.
As for schools, may I suggest thinking about U of Cinncinnati? Their classes may not be outstanding, but what allows their graduates to really stand out is the internship program. By the time you’ve graduated from there, you will most likely have about 4+ internships under your belt and hopefully some products out on the market. This is a 5 year school mind you, but after you leave, you’ll have the type of experience that employers are looking for. If you’re stuck on the places you mentioned, a nice place in Chicago would be Urbana-Champaign. Otherwise Pratt turns out good students as well. But no matter what school, it’s the student that makes themself good, not the school.
Your sketching will need improvement if it is what you say it is. The key is just to keep doing it. No matter how bad you think you are, just keep doing it and showing it. Allow for harsh criticism from everyone because it’s honesty from others that you will need to listen to if you are going to get better. Pick up some books on sketching people (how to draw comics the marvel way) as well as books or websites of sketches with robots, hardware, products, whatever (www.artbyfeng.com, pretty advanced but you get the idea)
Whatever you decide to do with your life, above all else, have fun. If you aren’t enjoying what you’re doing with any part of your life, find a way to fix it, even if it means starting over. You only live once (pardon the cliche).