Re: When do you teach your personal style?
To paraphrase Okumura Sensei:
up to Sandan be technically correct; Sandan to Rokkudan introduce your own personality; after Rokkudan do what the hell you like.
So on that reckoning Sandan is when you can branch out. However, Aikido is a reflection of your personality so it's virtually impossible not to introuce some facet of yourself into whatever you do in the dojo.