Plugin activation/deactivation with WordPress Multisite.

Please let me know if I'm seeing things correctly ...

[Please note that the settings "Enable administration menus (Plugins)" has always been disabled at my site.]

I installed 16 plugins in my Multisite website and network activated them and they were active in my main subsite as expected.

I then network de-activated them but found that the 16 plugins were still active on my subsite. Is that how it should be (I thought that by network de-activating them they'd then be de-activated in the subsite)?

Then one other thing happened. I installed another 10 plugins, did not network activate them, but they did not appear as new plugins that could be activated at the subsite. Why would the 10 new plugins not be appear as being available? The Activating and Deactivating Plugins on a Per Site Basis section of the WPMU Dev manuals says "Any plugin that has not been enabled for the entire network on WordPress Multisite can be activated on an individual site", but the 10 new plugins do not appear to be available on my subsite. Why would that be the case?

Thanks ... Michael