How would the Traxxas TQI radio with ipod dock be for racing 4x4 SCT. I have one from the Slash I have and was considering using it to race the Tekno410 I have coming. Any issues I might have? Or would I be better off ponying up for a better radio?

It will be fine to get started racing, especially in 4wd SC. In fact, it's response time will be on par with other entry-level radios and better than the super-low end Chinese un-brand ones, no matter how much time and effort is spent "hacking" those. I would use it until you're ready to jump all the way to something like the Futaba 4PLs.

I used an RTR HPI remote for a few months before upgrading to a Futaba 4PL and then to an Airtronics MT4... Not a huge amount of difference IMO. As long as the remote is comfortable you're half way there.