1) If the same DoPossess or DoSpawn AI scripts exist for the conjurer squad to have this then it should happen but..
2) Depends on the prereqs needed to do either the DoPossess or DoSpawn or..
3) Depends in the UnitStats.ai file how "favoured" the Sorcerer is verses how the Lord is. Seems like the Lord is more favoured but could be cost-related also..
Depends on some factors but not hard to investigate if someone has the code