You have touched on something that I believe is of utmost importance--knowing how the child is doing. Sometimes teachers don't do that, not always because they don't want to, often because they have fairly busy schedules (like many parents) themselves. But STILL, parents and teachers should keep in contact with each other, especially on an elementary level.
Actually, fairly easy, at least here. Keeping touch with the teacher by email helps or a well-placed phone call or volunteering in the classroom. If a parent gets to know the teacher and lets her know her concerns and that she is "keeping watch" (in a non threatening, but constructive criticism type of manner), the parent and teacher can have control. If they both are on the same page, then the child often gets on board too. I'm not saying things like this work everywhere and in every situation. Back home, the parents have always had a good degree of control because they have determined that it is THEIR community schools. They were instrumental in having my high school principal (who was super) retain his job some years ago. About 1000 parents turned out to support him in a confrontation with the school board.
Here, any secondary parent can log on to a website and find out how his/her child is doing in any class and what homework he/she has. Parents like that.
My own parents (and my brothers and sisters with their kids now) were a little strict with us, but it did benefit us. We had strict curfews on weekends (and required to wake up mom and dad when we came home), TV was somewhat limited, we didn't have video games (despite them being widely available) or cable TV for that matter, we weren't allowed to have friends over on school nights from junior high on, we were expected to get our homework done, we were expected to LEARN something from school and to inform our parents what that was, we were expected to be good examples and respect teachers and others, and so on and so on. My parents taught us how to deal with things when certain situations came up. Not to mention, we were taught to always remember where the Savior stood in importance to our lives--actually, it was church and family equal or more important than education and MUCH more important than "other" secular things. We went to inner city type schools, yet again, my parents made sure we got good educations (as are my cousins and siblings with their children in schools of all types now).
I don't think I'm any answer. I do hope to be when I am able to raise my own child, something I wish for every day. Parents like YOU are indeed the answer though.