What are the common points to take note, if we are unable to view certain portions (buttons, text boxes) in Sharepoint, after accessing via SSL VPN?
I can only speak from experience, but we found specifically with our Sharepoint Wiki site, that we had to remove the toolbar, in order to see the drop down boxes with icons (user role x -> UI Options ->browsing toolbar -> Untick 'Show the browsing toolbar')
Hope it helps.
Is silverlight installed?
all paths allowed?
caching policy (typically unchanged is your best bet)
depends on where the failure is happening on what to check