I use one battery, and have for quite a while now. I don't use an IBEC either, as everything I'm flying can handle the 6.6v coming from the LiFe/A123 battery packs I use as is, without stepping it down. There's no voltage regulation necessary to eliminate the second battery...

I use an Rcexl opto switch, as do many others. The fact it's made by the same people that make the majority of ign. modules shouldn't be ignored.

There's nothing unusual about this set up. A LOT of guys are flying it...