As you can see I am new here.

I started to play a trio of Warrior, Priest and Warlock recently (level 30 now) so I don't have that much experiance, but I hope my answer will help.

First I would recomment not to play the mage as a main. It is pretty difficult to navigate the Warrior in to closecombat range.

On the other hand, the mage just needs to face the target of the warrior.

Just have the Mage follow the Warrior.

With keyclone that is no problem.

Just block WASD, so it will not be parsed to the other client.

Then set up a macro on the 2nd client with /follow toon1 and map it to F1.
You should also delete the Keybinding for F1 on the 1st client.

What I found very handy was mapping one of the other chars to use ALT+1-0.

ALT+1-5 is very easy to reach. Also bindings like ALT+Q/E/R/F/C are handy.

With Keymaps that might be even easier to do.