I know you are asking for advice from veterans, so in that respect I have to clearly state that I am NOT in that category. I am a guy who has taken a 2 day course (which everyone on this board will rightly recommend to you, if not the 5 day) and has a rig coming in two weeks. As a guy who has taken a very different path from the veterans on this board, I can't speak for them. What I can say is that I have broken a million rules in my life, and I appreciate the fact that you are looking to do the same thing. Having a passion is central to getting anywhere in life. Look around you. Every man and woman on this board has done nothing but drive themselves towards the goal of developing their craft. They share a passion. That being said,
The unfortunate circumstance that you are presenting is that you are looking for a quick way through a path that is anything but. Garrett may have said that anyone can operate a Steadicam, but the part I think that people tend to leave out is that he probably also said something like "it takes years of practice to not suck." When you are asking a professional who has taken years to hone their craft, risked their personal relationships and their primary homes to invest in equipment to hand you their gear, you are showing that you are missing the most key piece of equipment in any operator's kit: humility.
The other thing is that you are valuing the accomplishment of "holding the camera" over the experience of knowing what to do with it. Yes, it is important to have a vision, but the experience of spending time on set, in whatever capacity you can, should not be lost. Steadicam operation is the only position I know that interfaces with every aspect of the crew - you are going to need the grips to hollywood 4 x4s on a windy day, tell the sound recordist you won't fly tethered, confer with the gaffer over what' s in the shot, coordinate with AD's so that the blocking makes sense in your frame, etc. There is no other day player that plugs into the set like that. You don't develop that overnight. That's the bad news.
The good news is that every moment you spend working up to it (and that's all of them) pay off. So take all that passion you have, and pour it into wherever you are going to be. I highly doubt that it is going to be a place where a seasoned Steadicam op is handing you his/her rig, but if it is, congratulations.
Jim
BTW, I am printing out Mike's response and posting it on my wall. If you don't know who this guy his, spend 20 minutes on his site before sitting down and taking his advice. I will.