Volunteer work is just that. You're supposed to volunteer. It's purpose is to show people the value of sacrifice. Doing volunteer work for Government compensation is called being a Government employee. Plus, as a former low income student I can tell you programs already exist that allow them to go to college for free and they're called Student Loans. With a part time job you can pay your living expenses and through grants and loans you can pay for school with very little problem.
Health care's screwed up and it should be cheaper but I don't want to send the message that it's ok to live off your parents at 26 years of age.
I don't have a problem with loan forgiveness for graduates that serve impoverished communities but that already exists for teachers and public servants.
Finally, while micro-loans seem like a good idea it would almost certainly end in a huge cash drain with virtually no pay off. Programs like YC work because they educate while funding. A 22 year old with little work experience who thinks the answer is to turn to the Government for money stands almost no chance of creating a successful business imho (and as someone who knows his fair share of entrepreneurs I've found most will tell you their first venture failed)