((The following has nothing to do with the TB -- just wanted to state that none of the below is a result of the TB, this is how my car has always felt since I bought it))
I've never felt 1st gear to be of any use, to be completely honest. I've always had to FORCE myself to use 1st gear and over time I've finally gotten to the point where I can almost keep up with city traffic during rush hour when the light turns green. Otherwise it's embarrassing that the light turns green and the huge SUV next to me that's an automatic takes off like a bat out of hell and I'm barely moving
After driving my car around for a week last time I had a company vehicle my dad likewise commented that he felt 1st gear was useless unless you're winding it out to 4-5 grand just to get going. He told me to use 1st gear anyway, but he at least understood why I was just taking off in 2nd all the time. If you're trying to shift at 2-3k, 1st gear is completely useless. With the ported throttle body, though, 1st gear might be even better if I'm trying to keep the RPMs down... honestly didn't get to drive it enough to really know for sure. I'll have my car back this coming Tuesday evening so I'll be able to report back then. We'll see if my dad notices any difference -- it's been about a few months since he drove my car last, but my mom has a 2012 LFX 2LS (automatic) so he knows how the 2LS drives.