Engine Anti Ice
Answer to # 1473
On the subject of Engine Anti Ice below -40, or not: you will get your answer if you read the Boeing Bulletin.
Engine Anti Ice heats the cowl inlet lip and the spinner bullet nose. In that way, it prevents the build up of large chunks of ice, that may break off and damage compressor blades further down the engine. To be used in regions of supercooled droplets.
Ice crystal icing takes place inside the compressor section of the engine, there where Engine Anti Ice does not heat anything. So, turning on TAI below -40 serves no purpose. Ice buildup on cowl lip or spinner does not occur, because the ice crystals bounce off them.
In general.
On the subject of pitot icing: yes, it can happen, on Airbus as well as Boeing.
TAT probe icing happens as well, probably more often than pitot icing. It can be observed from the TAT anomaly phenomenon (again, read the Boeing Bulletin). For crystal icing to occur, you do not have to fly through any solid wall of red, just the light green outskirts will suffice.
On the subject of stall recovery - even when not stalled, when ever is 15 degrees nose up an appropriate attitude at FL 350 in a big lumbering airliner?