2. Your setting a horrid precedent for future legislation, if you were looking to be introducing conscription that is exactly how you would go about it.
This is ambiguous to me, so I'm going to stop you right there. See, the military is one of the most powerful organizations in this country, and it doesn't want conscripts. It doesn't want a draft. It doesn't want anything along those lines, and it never will unless it absolutely needs the manpower, because they are a nightmare to deal with and do all sorts of terrible things to the quality and morale of the service, whatever service it might be.
There will never be a conscripted force in America short of WWIII/IV, because the military itself will never stand for it. There are no civil programs that necessitate conscription that the government wouldn't be happier just contracting out to private companies (for example, all the service industry work in the military) either. This is a "hey, do . .. .. .. . in your community we can't be bothered to find some other way to do" initiative.
5. Please explain the logic of paying people for volunteering
Um, so they volunteer?

You think people volunteer to teach in inner-city schools for five years to pay down their debts out of the good of their hearts, or because it
pays down their debts? This isn't rocket science. And how else is anything defined in government? By a committee.
Also, I want to point out 50 hours in Middle School, which is typically in two 16-week terms of five days (ignoring holidays), is 3,840 hours of actual school-days (ignoring weekends). That means that you could get away with doing about 20 minutes a day, every school day, or an hour every three days. Double that for college.
Oh noes, the horror,
the horror, it's the end of the world as we know it! And I feel fine.