Let's see, we got a 4+, two 5s, four 6s, one 7. Five of the rituals are based on net hits for duration, two others involve a secondary test instead, the third uses hits.
If you have Sorcery 6, Magic 6, a Focus Force 3, a Specialization in Ritual Spellcasting, then the odds on 5/6/7 solo are approx 72%, 52%, 33%. If we assume you get +4 dice from teamwork with a single other mage, those odds become 88%, 75%, 58%.
Rituals appear tough straight out of chargen, even if you focus on them, but then again rituals can be incredibly useful and you still have some wicked options even if you don't have a killer ritual team. However, the really badass stuff should be left to NPCs.