To be honest Seth, if the coach is so poor that they focus on what you mention, whilst playing tackle, then its highly unlikely said coach would use the advantages of playing touch/tag to develop other parts of the kids games either.
Disagree on this one, with regards to development, theres nothing you can develop playing touch/tag, that you cant develop playing tackle, theres plenty you can develop playing tackle that you cant develop playing touch/tag.
With regards to safety/long term well being to the kids, thats a different story and somthing i would never claim to know too much about, but if it is somthing that is proved to be beneficial in these areas, then that is the most important thing and well worth holding off the contact for a few year