(1) Have you tried System > Preferences > Internet and Network > Network Proxy and set address ranges in the Ignored Hosts tab?
(2) I've never bothered with face browser, but GDM (which manages graphical login) is being completely re-written and is still missing a few features at the moment, so that may be why.
(3) As posted above, Plymouth does not yet support a wide range of video cards by default, although future versions will expand support. See
this thread. You may also need to search this forum for "plymouth graphics" and search Google for your particular VGA mode.