You will find that the jurisprudence surrounding those clauses bears no resemblance whatever to what the clauses actually say. For example, look up Wickard v. Filburn and see if you think that Supreme Court decision used a reasonable interpretation of what Congress can regulate under the guise of "interstate commerce".
Interestingly, though, the clause under which the individual mandate was found constitutional was actually the Taxing Clause--the Supreme Court said it was not constitutional under either the Commerce Clause or the Necessary and Proper Clause, which was how the government had argued the case. In other words, the Supreme Court said that, while it was not constitutional to require everyone to purchase health insurance, it was constitutional to tax people who didn't. Go figure.
The full opinion is here:
Wage controls during WW2: http://www.npr.org/templates/story/story.php?storyId=1140451...
Without either the individual mandate (which is itself a half-assed approximation to single payer healthcare) or group health insurance (through employers or some other non-health-related cooperative), people put off getting health insurance until they get sick, the risk pool stops being a pool and the whole concept of "insurance" falls apart.