So recently I got taken with the idea of playing a wizard's shackle (the leeches that attach to wizards and mind control them from bestiary 5) taking levels in wizard and riding his cohort also a wizard.
Upon solving the issue of how to get a cohort early on (I stumbled on the instructor wizard) I picked out a school of magic (conjuration [namely teleportation subschool for the short range blinking about for if I need to travel without my standard pair of legs.]), unfortunately as I was picking spells and feats I realized I can't speak except through telepathy and I can't wave my arms because I don't have any.
Is there some way to get still and/or/and silence applied without having to cast cantrips as 2nd levels spells or some way to circumvent the whole can't use verbal or somatic components.
I don't believe there is a way to do either, nor can I think of anything even a lenient GM (which you obviously have) might invent to solve the problem for you that wouldn't wreak havoc in the world. Spell components exist for a reason. Maybe you should go for psionics or psychic magic or something instead?
I had the same problems playing a Tsochar back in ye olde D&D 3.5e, at least when inhabiting bodies I wasn't actively controlling. My solution back then was to play a psionic character rather than an arcane caster, so perhaps look into Pathfinder's occult classes to get around verbal/somatic components.