Everyone is different but those who seemingly have low-grade cancer should absolutely consider AS until the psa begins to rise and/or subsequent biopsies reveal further cancer. For those on AS or considering AS, the stress will be there but after a primary treatment the stress is even greater because you have added the element of certain quality of life issues. Therefore, if one can, he should delay the quality of life issues as long as possible.
As to taking supplements, I say why not? Just be certain that what you are taking doesn't impact the affect of other things you may be taking (ie. pomegranate and statins don't mix) and that you don't go overboard by believing fake advertising on those trying to take advantage of us. While conventional science says supplements do not help, there are TRUE success stories out there. However, be advised that what works for one, may not work for another 100 and some things can actually hurt you. Therefore, if considering supplements, DO YOUR HOMEWORK!