Sure, that's part of the equation now, but it's not the cause at all.
In order of your suggestions:
1. Reduce administration and administrative overhead, not necessarily the salaries. You want competent people in administration but not every one of them needs highly paid assistants. The percentage of total cost devoted to administration is too high. As for non-teacher salaries, you'd have to be more specific.
2. Great, but how. A lot of parents don't want to be involved and it's hard to make them be involved. And a lot of kids have one parent who's trying to work and make ends meet for a family on nothing. Or the kids are in foster care. Parental involvement, even if it's just helping with homework and getting the kids to school on time, is huge. But it's easier to talk about than to make happen.