Although I've been pretty successful in doing more than one thing at a time, I'd recommend that you concentrate all of your energy and focus in one business, to get the most out of it.
I'ts my nature, to be constantly aware of everthing around me, I love the hassle, and pressure of start ups and get bored, when things run smoothly, so my life has been, very much, about new ventures and helping others get up and running
This is not, however , the way to go for 99% of people, who need to be focussed on one business and devote all of their energies in one direction
robbie