As an Arlington resident myself I have a love/hate relationship with Lone Star here. I just started attending their FNM and those have been great, but outside of their few Magic events there is really nothing that gets me into the store. With no singles, and a rather limited MTG stock (both card products and accessories) I have no reason to spend my time or money in store, and with the closest shops with a better selection being EVO in Ft Worth or Cosmic Comics in Grand Prairie most of my money gets spent online.
Travel wise I can't get much closer to Lone Star than I am right now, I would walk there if it wasn't so hot. But at the same time I'm more than willing to drive a reasonable distance (less than 10-15 miles) to someplace if that means more magic events, singles stock, and a better selection of accessories. I'm no expert on running a business but the card shops I've liked the best have either been big enough to devote decent space to card games while keeping comics/board games/other typical nerd products or have been highly focused on TCG/CCG or just Magic specifically.
The short list to win me over would be: Singles, more events (like magic almost every night of the week), SATURDAY EVENTS, SATURDAY EVENTS, SATURDAY EVENTS. The rest is all dependent on the community you attract, but that's something you wont know until you open.
I really just want to play modern on a Saturday afternoon without having to drive for half an hour.
Best of luck with the store, I'll be sure to check it out if you go through with it.