I think 2 weeks is doable -
I would like to add my 2 cents but first of all to other readers even though I never really post here as I had never done a cross country trip before August - all the contributions and ideas here on roadtrip america were a huge help in planning and implementation.
With that said - gage - I think you can do this. My daughters (ages 17 and 21) and I (husband opted out on this one) drove from Los Angeles to New York. Left on a Thursday and arrived in NY the following Thursday. That included a full day (2 nights) in St. Louis just to have some non drive days. We sort of "shadowed" route 66 for parts - stopped at of the places that interested us. Drove no more than 9 hours in a day. We veered to Santa Fe and spent a morning checking out the annual Indian Market - we also veered off to Cleveland to spend a morning at the Rock N Roll Hall of Fame. We never ate fast food - sit down dinner or lunches only. The girls loved it - but in a time crunch we could of easily done it one day quicker.
With that said I think round trip in 14 days is totally possible - its clear that's what you want to do - I say go for it. If you want more details on our route since we started in LA - your destination I can elaborate more.