I think therapists who have a past do make wonderful therapists. I believe they "get it" because they lived it. When it comes to SI I would have a very difficult time if it is obviously recent. For me SI typically means they are quite depressed and quite possibly SUI. When I get depressed I often feel like I can't anymore and waiting for that one more thing on my plate which will put me over the edge. I have cut only a handful of times and has always been when when I am near that breaking point. If my therapist is at the point of recently cutting I would be afraid something I said would trigger her or whatever and push her over the edge.