CaliBaller, here are my thoughts on your questions.
1. It really all depends upon the integrity of the coach. I've consulted with parents who were told that their son had a "guaranteed roster spot" and then found out that 9 or 10 other recruits were told the same thing, when there are only 8 walk-on roster spots on most Div. I teams.
2. This will be true at the majority of schools.
3. I agree with justbaseball on this one also.
4. A few other things to keep in mind include: a) if it's not too late, your son may want to stay a "non-recruited" athlete so that he'll have the chance to be eligible at another Div. I school if he chooses to transfer; b) you may want to check out the track record for walk-on players at the school where this coach was previously by looking ar rosters for the past few years at that school;, and c) you may want to check out the following blog on our website, as well as resources in the "Store" of our site, such as our "Informed Athlete's Guide to Campus Visits."
http://www.informedathlete.com/walk-on-transfer-rules
Rick
Rick is right. You need to try and find out how this coach as treated others in this same position in the past. Some programs are absolutely truthful when they say your son will be treated like the scholarship athletes, others just say this and do not honor the promise. Do your homework by talking to ex players of coach and program.