In case of wraithstrike you cannot use it as stance but a boost maneuver likely as it's swift action activated. Most any spells which are naturally swift action are boosters while immediate action based (like Wings of Cover), are counters. Standard/Full action spells are then strike maneuvers. 1 hour or 1 day per CL spells are stances usually but again as GM I need give approval for the stance spells (as some may be plain silly like Mordenkaine's Mansion or Secure Shelter). Idea is that spells must make sense in combat wise; or provide utility to combat (so casters are not outclassed by swordsage in utility fields).