1. The quickest that someone can become a CRNA is 7yrs assuming that you do a 4 year BSN program (4yrs BSN, 1yr acute care experience, and 2yr NA school). The COA is trying to make CRNA school a mandatory 3 years. That would make the minimum time 8 years. Most nurses will spend 3-5 years in ICU before going to CRNA school.
2. GPA for admissions is usually divided into overall GPA, science GPA, and the last 60hrs of your BSN program. Graduate hours are usually looked at separately.
3. These questions have been answered on here several times, but the best place to find these type of answers is to go to the nurse anesthesia schools you are interested in and look at the admission criteria. The AANA also has a section for people wanting to become CRNAs that give the basic criteria and detailed explanation of what CRNAs are responsible for and can do.