Some answers to your questions...
1. Is there a timeline/deadline for one to pursue this route? What I mean is, is it required that you apply for DUINS after your first tour (3 yrs) or can you have that option after say 6-8 yrs in the Navy?
Nope, no specific timeline, I went to DUINS after having been in for 9 years and after my 3rd duty station.
2. Has anyone gone the DUINS route for Nurse Anesthesia? I realize this is highly competitive in the military as well as civilian route but was wondering what some experiences have been with this.
I went for something else, but have had friends that went this route. It's a very time consuming program and you'll be plenty busy. Following graduation, you will be highly deployable.
3. Is it true that while in the DUINS program this is your only job? I.E., you don't do shifts as a nurse during this time as well?
Yep, that's all you do is go to school. You still have to take the PFA every 6 months, otherwise it's like being a college kid again, oh but getting paid for it.
4. Is USUHS the only place to participate in the DUINS program at or can you (for example) be stationed at San Diego or some place else and attend a CRNA program where you are currently stationed? Basically, would you be able to attend a school near your current location or would you have to move to attend USUHS?
Yes and no. If you go the CRNA route then USUHS is your school. They used to have a 2 places at Georgetown for people to go to, but most all go to USUHS. As for the other DUINS programs, you can just about go anywhere. I went to the University of Maryland, there's a list of schools that people have already gone to that we use as a guide.
5. Will entering into the DUINS program delay a promotion in any way?
Nope, I picked up my current rank while in DUINS, doesn't delay it a bit.
6. What is the time committment added on to your current committment after graduation as a CRNA? 4 years? 8 Years?
It's 2 years committment for every year of school the Navy pays for. Got to a 2 year grad program and you have 4 years to pay back.
Hope this helps.