No, I think you can make it work. I'd probably still do the air->water->guidance shuffling for your last spirit type. The main things to keep in mind would be:
Remember that being possessed is super obvious and not at all subtle. Don't make plans based around being able to self-possess 24-7.
Possessing yourself is a good way to not die, because it gives you a lot of defenses, but only if you are possessed by a decently high-force spirit. Possessing yourself with low-force spirits is bad times. An Air Spirit with Elemental Aura is a good choice for this because Movement and Concealment work nicely with innate pixie powers, and it can attack very effectively while possessing you with Engulf+Elemental Aura.
Make sure you have a reliable thing for any low-force bound spirits you have around to inhabit. Homonculi are probably your best bet, since you don't want to use corpses and drones are probably not appropriate to your tradition. Plasteel Homonculi are really, really brutal (again, Air spirits with Elemental Aura). Wicker men are very cheap and are OK, and are better than Plasteel for spirit types that fight with powers rather than physical attacks (eg, with Fear, or Man spirits that are going to be spellcasting). Living heavily cybered dudes are great possession targets but also not something you can run around with all the time. Possessed heavily armored vehicles are really brutal, but also very unsubtle.