Yeah... a decent class conflict model of inflation has to have money in there somewhere, and once it's there you can't put inflation down to either as a unique cause... one is the condition for the other. There's a tendency in some models to treat money as simply accommodating, which is not always true, and which cannot deal with cases where exogenous monetary developments are the spark.
Of course, incorporating money doesn't have to be done in a monetarist way. Most mainstream models these days focus on interest rates rather than money supply anyway. To capture what's happening at the moment, though, I think you would need to deal in a pretty complex way with quantities as well as interest rates, and interest rate spreads rather than a single interest rate... The question is really what bank balance sheets are going to look like once things start turning up.
Technically, theoretically, politics aside, there is no limit to the amount of debt the US government could take on and repay just by printing money, and it's in a better position to do that than any other state. But of course it would sooner or later have an effect on the value of the dollar, both in terms of inflation and the exchange rate. The big question is how far it can go, and no-one really knows because it depends partly on the expectations of bondholders.
Mike Beggs