Living in Uptown and commuting to Irving and Plano is very realistic, as you are going against the flow. Yes, it will probably take a half hour, but it isn't like you are stuck in traffic. Ft Worth, no. (I'm sure there are some that do it, I too have coworkers that commute an hour+, but that is not what I would choose.)

Don't count on DART. I know the WMATA has issues, but DART is not on the same level. You might luck out and it will work for you, but go in with the assumption that it will not. But for all of this, do you know where your office might be? That will affect the answers given.