Key reasons: benefit to the planet, it takes a lot less resources to grow vegetables for food consumption than it takes to grow cows (also responsible for disappearing rain forests), plus, it doesn't support factory farming practices which are not only horribly cruel to animals in that they have horrible living conditions, but also, this type of farming is environmentally destructive.

I was veg for about 6 years. Health benefits (if you do it right with nutrition focus), you can find a better pH balance. Most people in our culture are too acidic, meats, dairy, animal products, and even beans and brown rice are all high acidity pathways in metabolizing in the body. Because the body needs to maintain a balance, it draws Calcium from the bones to counter the acid levels of metabolizing these proteins. A main cause for Osteoporosis is this high acidity level (if it were just about getting calcium, US would not have the highest rates of milk consumption and osteoporosis).

America would do better to eat less meat, and more fruits and vegetables. We need only a fraction of the protein we are getting daily.

In truth, health insurance works a little differently in each state.

To answer your specific questions:
1) No, health insurance is not compulsory for everyone. If you're lucky, you are able to join a group policy at work. (If you're really lucky, it's a good policy and the employer pays at least half of it.) Some states have recently made it compulsory, but that's such a recent change that there's no clear cut answer yet for how that's going to work.

2) What happens if someone can't afford it is… they don't get it, usually. Except if your income puts you below the "poverty level", in which case you qualify for Medicaid. (In some states there are programs that typically provide assistance with insuring children, though they are few and far between for covering adults.)

3) Health insurance rarely covers all the bills when you have a procedure done. Most plans cover 50-80% after you meet your deductible. The deductible amounts vary widely (but the trend is that the deductibles are getting higher and higher to keep the premiums down.) If you're really, REALLY lucky, you don't have a deductible (which is only an option on group plans), and you may only have to pay 10% of covered charges. (These plans are few and far between. As in, you might have them if you're in Congress.)

4) Yes, the patient has some say over procedures. However, if the patient opts for an "experimental" procedure, or one that isn't deemed "medically necessary", then health insurance may refuse to cover any charges at all.

In the end, as with most things, the middle class takes the brunt of these costs. This has become such a problem that more than 50% of all bankruptcies are as a result of medical bills (and of those, more than 75% had health insurance.)

** Edited to add:
It's not ALL about the money when a procedure is involved. If it is, the state keeps track of complaints filed on behalf of consumers with "managed care" (ie. any type of network arrangement including Preferred Provider Organizations, Health Maintenance Organizations, and Point of Service organizations — also known as PPO, HMO, and POS) and may very well revoke a company's charter to do business in the state should the company be turning down too many legitimate claims.

However, insurance companies are sticklers for following the "standard" for medical care. This is what makes it difficult to answer your question. Because they should not deny anything that's considered standard for care in the given circumstances (should not and will not being two completely different things, of course.) And there may be several options that would be considered "standard." If the patient wants treatment that isn't yet considered "standard", they would balk. Period.

An even better start is a web search in Yahoo for "alternative health techniques" that will yield at least 412 results including overviews of alternative health techniques and stacks of other useful information for you.

Another useful search in Yahoo for "alternative health practices" will yield at least 2,888 results.