I will most likely end up writing the DAT if I am not accepted this year. I was informed that JCU sends out early offers but only to those who they consider highly qualified candidates so I was not really sure who would fall into that category. I have sent my application and am hoping for the best but do have Adelaide as a backup option. From all the dental schools they have the most spots available for international students (~40).CSU's first round offers took about 3 weeks after the interview to be released. From my experience, CSU is very holistic unlike schools like UQ where you get screened out for not meeting their cutoff. According to Oztrekk, there were 7 acceptances after the first round, and I saw this other guy on SDN getting a second round offer.
JCU has already sent out 6-7 early offers in the beginning of July according to Oztrekk. The program should be half full by now.
Definitely do the DAT. It will open more options. You can at least apply for Sydney and UWA if your DAT is high enough (eg. 22+ for UWA interview and 19-20 for Sydney MMI).