I think we're blowing this out of porportion a little. I think what the OP is trying to tell us is that he wants to focus on his local markets that provide the most news relevant for him and does not want to complicate his system just to pick up network duplicates.
camou10, you've had two people recommend the same antenna to you. Now, make it three. The HD7694P aimed a little south of due west will get you the Baltimore market and a good chunk of the DC market. Some plusses: the CBS and FOX stations will show different football games, WETA and WHUT will show different programming (or the same prime time programs at different times) than the MPT stations, and you will get most of the major sub-channel networks like This, RTV, CoolTV, AntennaTV, etc. For a complete list of the sub-channels you will get, consult
RabbitEars. Under the listings menu, select Web Listings, then click on the market to show the major channels and click "Expand All" to see the subchannels.
The networks you questioned: qubo is a children's channel, MyN is the Fox Network's answer to the CW, and came into being when UPN merged with the WB to create the CW network, and the other two are Spanish-language networks.