Why would anyone want Soriano in the first or 2nd spot? He Ks so freaking much it's ridiculous. I think he really hurts the team batting there....and I think you're looking at this too much from a fantasy perspective to realize it. Think about it, Blalock and Young are the best pure contact hitters the Rangers have, with Teixeira a very close 3rd. Dellucci will be a lot better this year following his LASIK surgery, thus the increased walks. I think Dellucci is OK as leadoff, at least until he proves otherwise. Young is the ideal #2...great contact, good speed, few Ks, good OBP.
I don't see any argument whatsoever for batting Soriano first or second. Third is a stretch as well, but at least it would be better than 1st or second. Soriano 4th with Teix or Blalock behind him wouldn't be a bad option either, simply because he would see some great pitches to hit because pitchers wouldn't want to walk him. Still though, I'll stick with my 5th spot theory.
Also, regarding the left/right thing...you're right that it won't really affect how the starter pitches, but it could really cause havok towards the end of the game when the situational relievers are brought in. Having a left/right split all of the way down the roster would be almost unheard of...and it would at least be interesting to see how it works.