Maria's up to level 12 now, serving as a buff-a-matic in groups, and using summons to kill for her when she solos, or travels with only other casters, and she's cast many monster summonings and animate deads along the way.
So, now that I've said that part, on to the actual topic, durations of the summoning spells, and possible other changes.
Monster Summoning I - Duration should be 1 hour, plus 1 hour per level. This spell is only used for actual fighting at low levels. At higher levels it's used as a distraction or for springing traps, so duration is almost irrelevent. As for it summoning a Dire Badger, I can't remember ever seeing one in the setting. A normal badger or wolverine would be more appropriate.
Monster Summoning II - Duration should be 1 hour, plus 1 turn per level. Maria dropped this spell, because it's the most useless of the summons. Most times it was either dead or unsummoned by the time it finished becoming enraged. The only reason I don't have this spell at an hour plus another per, is that animal domain priests summon dire wolves off this spell, and that would be far too long a duration to have it. As for monster type, a razorback would be more appropriate setting wise.
The durations for MS III and up are fine. If MS VI could be renamed to "Massive Dire Crag Cat", a bleached version of the normal Dire Tiger, it would be more fitting.
I haven't had a chance to use the level 7 and up summon spells here, but from what I've seen of them they all last long enough to kill what needs killing.