For the body questions, the horns are a body part just like any other in that instance, so they can be wounded just the same as hands and feet. Also, those attacks will work just fine, though they are rather powerful.
For the buildingdestroyer question, I think that they would put both of those things on about the same priority, and just go for whatever one is closer. I am not sure though.
Some of the personality tags can affect creatures a lot, but not quite that much. Setting a creature to have a higher anger in its personality will cause it to go berserk more and make it easier for it to 'fly into a rage', but it will not make it be a constant thing, not even at 100.
[FAT:?] doesn't have anything to do with a creatures ability to survive hot and cold temperatures, it just determines how much fat a creature drops when butchered. For a larger range of temperatures, I have found that [LAYERING:50] is probably the best, allowing creatures to survive in some of the colder temperature zones without really reducing their ability to live in the hotter ones. Any more than that and they will probably start to not be able to live in some of the hotter deserts. For a creature that can survive anywhere, add the [COLDDAM:0] and [HEATDAM:12567] tags. That will create a creature that is completely immune to basically all temperature effects, short of being immersed in magma.
In my experience, [trAPAVOID] will allow creatures to avoid all traps except pressure plates except for cage traps. In the event of cage traps, it seems to reduce the chance of being caught to a percentage. As for the escaping, I have no idea.