I see from your profile Karrank that you are the one that sits in the armchair. Maybe you need to revise your understanding of TCAS.
You are correct in that a pilot needs to be proactive in safety. The correct procedure for a TA is to try to visually acquire the traffic. If you cannot acquire the traffic the do nothing (follow your clearance) until a RA occurs. Is this safe, yes. Would I follow this, probably not. I would reduce RoD back to the minumum of 500fpm (which by the way still satisfies an ATC clearance to descend). If I thought that a level off was required to maintain separation, I would request this from ATC. However, I wouldn't turn the aircraft.
Turning an aircraft away from an UNSIGHTED aircraft based on a TCAS TA isn't the correct procedure. For starters the update rate on TCAS is poor, if you look at traffic on the TCAS display and then turn onto a new heading, the traffic moves around significantly before settling down to its new relative position. In the future we will have fast update rates based on transmitted GPS position, which will solve alot of problems.