Management of Apple devices, user accounts and other items

For my sins I have a predominantly Apple-centric network at home consisting of:

• Macbook (stuck on Mountain Lion)
• iMac (stuck on Mavericks due to ATI 5750 driver issues on later versions)
• Multiple iPads, Pods, and Phones.
• QNAP NAS
• WNDR3700 ruing Gargoyle (Open-WRT)
• Netgear unmanaged switch

What I'm trying to achieve:

• Manage user accounts better as more machines (kids homework etc) come onto the network. Would be good to tie in computer access with NAS logon etc. Radius?
• Control machine access better - including limiting them from using the primary iMac
• Access restriction. More on bandwidth quotas but also limiting time on device.
• Download caching, especially for updates (iOS9 x 5? No thanks.).
• Would ideally like to standardise things such as every account using ClamXAV with download folder monitoring, Firefox with Privacy Badger and other add-ons etc.
• Would like the central machine configuration and maintenance i.e. not having to logon 5 or 6 times at each machine to set things up.

I have setup QSync for each user manually so that they have a dropbox style folder that syncs to the NAS and I could point TimeMachine there if I so wished. Access control has been more problematic with restrictions on YouTube not working particularly well although bandwidth control at the router is working.

The Appleness of the network does steer me towards OS X server though I'm not sure how much of this can be delivered by it vs perhaps an open source solution that wouldn't restrict the hardware platform (although I could build a cheap Hackintosh).

Has anyone managed a small Apple-centric network successfully and what was used?

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