Originally Posted by
ExLibrisMortis
Agreed with Tippy. You can remove any mechanical association with 3.5 spellcasting, for example by not requiring any expendable resource, but the ability to take other forms is going to be magic, no two ways about it.
You can do what (greater) teleport/plane shift does by 'slipping between the planes', using an Escape Artist check.
You can do what ice assassin does with a Craft check, fusion with a Heal check, and astral seed with a Survival check.
Are those things less magical because they are (Ex) and done via skill checks? I really doubt it.