wow.
no single coherent question asked yet.
iSync works well for syncing phones etc.
However, exchange syncing has proven problematic for many that have tried. There are other specific threads on this problem.
LDAP is a whole other thing - many servers allow for LDAP access in address book - it allows for entries to appear under the "directories" item.
At least some Exchange servers can be accessed via LDAP, but my experience is that you need to use port 400 rather than the normal port 389.
Try that (if indeed that's what you're trying to do).