Hi, pleased to meet you.
You appear to have what we refer to as a Gleason Score of 7 (3+4) or, G7(3+4). While many folks consider that 'intermediate risk', I personally consider even a single G4 cancer cell to be potentially fatal given that it can move around your body and colonize distant places (metastasize). The bone and cat scans are indeed standard operating procedure in our type of case.
The PSA of 17.3 is worrisome. I wouldn't sit on my hands too long as the stats aren't with you on that. (There are dotted lines at a PSA of 10 and another at PSA of 20. You and I are in the in-between on that. Not really wonderful.)
Mine was supposed to be 'clinically localized' too....but it turned out to be a little bit worse once they got in there.
As for 'active surveillance' or 'watchful waiting'...that would give you the opportunity to 'actively watch' your cancer go from a "stage 3" to a "stage 4" with all of the associated accoutrements.