Dear Michele:
You just described my daughter! At around 14 months in the space of one week she wouldn't sit in her highchair or booster seat, sleep in the crib or let anyone help feed her! It was a trying week until I changed my approach.
Instead of a crib we switched to a very low futon and a child gate for the room. Instead of a booster seat she just preferred to kneel on the chair. As far as meals, we had LOTS of finger foods, large bibs and vinyl tablecloths! Meals took longer, but I just brought something in to do while she was still eating and let her go.
It's messy and slow for a while, but your Miss Independent will be very proficient soon and at a younger age than other children.
My daughter just turned 14 and the independent streak continues. She's very mature, self-confident and a leader.
L. F., married to my best friend for 22 years, mom to a VERY independent 14-year-old daughter