Re: TCAS in a turn
The official advice is that a turn should be continued IF the required vertical speed/pitch angle can also be achieved - if not then level the wings and execute the required climb/descent.
(Ref. ICAO Doc 9863 - ACAS Manual, 6.3.1.5.d "if possible, comply with the controller's clearance, e.g. turn to intercept an airway or localizer, at the same time as responding to an RA")