7. Is applying a kernel patch or a Solaris patch bundle the equivalent to installing the specific Solaris 10 "update 6" image?This means that you have to update your OS using a complete release >= 5.10 u6.
No, it is not. The OS kernel can be updated to U6 levels (or later) with MU (Maintenance Update) patch bundles, or with the individual kernel patch. However, according to Oracle's Solaris team, this is not the same as the update level that Oracle Development built and certified 11gR2 with.