Mage - Need a bit of clarity (no, not mind candy!))

[PatriotPanda]

Hey Mages,

I'm picking up my 18 mage to play with my wife who is resurrecting her 14 enchanter (both of these chars are naked and my 28 druid is funding them for now.)

You guys have put together AMAZING guides on where to level - I'm left a bit foggy on the suggested mechanics / strategy for lower level mages.

1. At 18, and upwards through 39 or 40 when most guides say start chain summoning pets - should I just damage shield my pet and let it solo mobs?

2. When I played live I thought I remembered pets taking 50% of the xp if the mage didn't do 51% of the damage to the mob. Is this still true? If so, is it worth the ease of just letting the pet do the heavy lifting anyway?

3. (closely related to question 1) Many of the guides recommend not really nuking at all. If I tag a mob with a low level nuke, do I really get full xp credit for it?

4. During the fight - should I bother healing my pet, or just let it fight 'till it's pretty much dead and summon a new one?

Sorry for the noob'ish questions - it's been a long time since I've played my mage and want to make sure I'm maximizing my efficiency.

If it's relevant, I'll be playing this mage almost exclusively with my wife's enchanter. If she's not online I'll likely be levling my druid.

Thanks in advance,

Panda