urm...single weapon and two handed does indeed stack together...
you get the ac bonus when you have a single two handed halberd or staff equipped...
range don't give you two handed bonus or single weapon ac bonus...
sword and shield is the single most completely useless proficiency EVER...worse than useless in fact, completely valueless...
why? really simple, if you read the description for sword and shield you find spending prof bonuses on sword and shield will increase your ac against missile attacks...and in the adventurer's mart is a shield that will REFLECT ALL missiles thrown at someone...
so in the saughin city, or anyplace where there is a large number of missile attacks thrown at your party, just have lead tank use the shield of reflection...much much better than spending prof on sword and shield...
oh yeah, a single one handed weapon and a shield and two stars on single weapon will give you the bonus ac of single weapon....