Well, there are several in here I need to take a look at, but I will do the new guy's character first.
Reviewing Joren:
a) As you can see, my OCD is strong. I did a lot of little formatting things just to make it a little prettier.
b) You are carrying enough to put you into medium encumbrance. That will cause a -3 ACP to several of your skills. So, it might be a good idea to drop the grappling hook for now.
Suggestions:
A) I suggest going back to taking the FC bonus as an extra cantrip. Having an extra at-will spell is real nice. And you get to do that with three cantrips across your first three sorcerer levels.
B) See
Alternative Cantrips. They are extra choices that you can make.
C) To make up for that, I would take Toughness as a feat instead of Spell Penetration. As a mystic theurge, you are never going to be throwing the top end spells that need to break through SR. And you surely don't need the ability at low levels.
D) I would tweak the stats and drop WIS to 14, spending the extra five points in CON, getting a 14 there as well. That, combined with the Toughness feat, gets you +3HP per level, or a 75% increase per level. It only drops your Will save by 1. And you will get stat bump headbands long before you need them in order to cast spells.
E) Child of the Temple is a waste. As soon as you take a level in cleric, Kn Religion becomes a class skill. After that, the trait is only worth a +1. It is better to spend traits on things that cannot be easily taken any other way.
Suggestions:
Faith: Birthmark: Your will saves are comparatively very good. This brings them up to exceptional for charm and compulsion.
Faith: Beacon of Faith: +2 to Caster level on a domain spell is nice, even if it is once a day. Then again, you only get each domain spell once a day anyways.
Magical Lineage: Shocking Grasp + Metamagic Reach is a powerful combination for a low level spell.
or Magical Lineage: Cure Light or Moderate Wounds + Metamagic Reach is a powerful healing combination for healing at a range.
Magical Lineage Shocking Grasp + Metamagic Reach + Metamagic Intensified Spell goes a long way in being effective across your career. It is also a nice ranged touch spell, when you have a dex bonus. So, it is never a hard attack to land.
The only problem is the ACP issue from carrying too much. But, there are a lot of suggestions for you to mull over.
And I think Mystic Theurge is fine. All my characters are at least dual classed, with one triple classed. I seem to get by.

-SK