Hi slywolfe, here are some answers to your questions, hope it helps! Are you in nursing school, or still taking general undergraduate classes?
1) Bedside treatment: CRNAs' bedside duties are different from staff nurses. There are circulating nurses and OR techs who are responsible for many of the needs of the patient like the ones you asked about. (Poo is much less common in the OR than at the bedside). Baths do not take place in the OR or PACU. The extent of physical contact a CRNA usually has with the patient is to do assessments, help with positioning on the OR table, and intubation/line placement.
2) Majority of procedures: This does depend on your practice setting (inpatient, outpatient, clinic). CRNAs working in a hospital OR will do pre-op and post-op assessments, intubate patients, initiate and maintain the anesthetic, monitor hemodynamics, give some medications (for nausea, hyper/hypotension, etc), place IVs and occasionally other lines (CVLS, A-lines). Practice is limited by state, but many CRNAs do epidural and spinal anesthesia as well, and can do regional blocks (blocking a certain extremity for surgery, for example). Scope of practice is different by state, by hospital, and depending on the MDAs one works with. Some CRNAs have a great deal of repetition in their work (and like it!); others, like those working in trauma centers or large teaching hospitals, see a variety of cases.
3) The majority of the time, an MDA will be present in the facility to monitor cases. In large hospitals, there will be many anesthesiologists as well as anesthesiology residents who will do the difficult intubations and place most of the lines/blocks. However, there are small hospitals and clinics (mostly rural) where a CRNA might be the only anesthesia provider, especially in call or night situations. There is a wide spectrum of autonomy for anesthetists. CRNAs definitely have experienced the loss of patients, but when a very sick patient is having surgery, there is usually a team of CRNAs, MDAs, and intensivists present to monitor the case.
Hope this helps! Good luck to you!