Here is a good guide to what skills you should consider maxing as a wizard.
http://www.silkroadforums.com/viewtopic.php?t=58145
As for what skills you should max for your cleric subclass, you should definitely get:
Bless Spell
Recovery Division
You can also consider getting the following skills in order to fill in for a dead or absent cleric in a party:
Reverse
Group Healing(which you can eventually de-level for Group Recovery)
Body Blessing
Soul Blessing
Reverse Oblation(if you have the SP, else just stick with reverse)
As to your last question, your cleric mastery should be a few levels behind your wizard mastery as you go along. Eventually, though, you'll have both your wizard and your cleric mastery at 80.
Hope that helps.
