No need to replace the TSA, just the DHS and TSA senior leadership. Then, from the top, dictate some sanity at the checkpoints, like this:

Primary: WTMD, baggage x-ray, ETD as necessary. No more carnivals.
Secondary (alarms, SSSS, and random pickings): bag check and European-style security interview
Tertiary (interview "fail"): choice of pat-down or NoS

I see lots of pros and few cons. The primary rolls back most of the security theater that was added by that idiot Kip Hawley. The secondary replaces a physically invasive screening with a psychologically stressful, but more effective, one. Existing BDOs can be re-trained to conduct interviews. Maybe they'll actually start being effective in this new role. Relegating body searches to tertiary restricts the most invasive procedures to the smallest subset of flyers. I'm aiming for fewer than 20 physical searches per day, nationwide.

Yes, an interviewer can abuse power and kick a passenger to tertiary if they don't like his/her attitude. As this already happens today, we're not making the situation any worse. As for language barriers for international visitors, yes, that's a legitimate issue.