in a theme league, if there is DH in the AL and not in the NL, what happens during AL/NL play?  is it like in real life where it is used when the AL is at home?

Whats the smart play in a league that will be split - go into the DH league, spend the money on a hitter or go into the non DH league, get better players elsewhere and figure that you'll find a way to handle the DH with scrubs??

It's like real life.  The DH is used in AL home games.

I think it is only 12 games where a DH is used, I usually just play backups....

if I have a choice of being in the AL (and spending money for a real DH) or being in the NL and not, any opinion as to the smart move?  I have a suitable guy to use in the theme as DH, but I could spend the money elsewhere.....??

Go no DH.  I would much rather have to have less PA and IP.

Really, aside from the 12 interleague games away from home, doesn't it pretty much not matter until the World Series. At which point the NL team will have the advantage from the more cost-effective roster, especially if they some decent 500k pinch hitter to put at DH.

It depends a lot on the restrictions of the theme. But in general, I'm partial to using a DH myself, though I know a lot of people like playing NL and drafting one really good pinch-hitter type to use in high leverage situations and when playing against AL teams.