You can most definitely apply to medical schools during your ACP year. I chose to only apply to Tulane and I believe most people in my cohort did the same. One applied to her home state institution and was subsequently accepted there, and chose to attend due to lower tuition costs.
I'm graduating from Tulane SOM in three weeks, and I have to say that attending ACP and later matriculating into the medical school was one of the most rewarding and enjoyable decisions of my life. While not without it's shortcomings, Tulane is a great school in a city that can't be beat.
Aside from that, ACP students historically have done well in medical school. In this year's match, we had two go into ortho, 4 EM, 3 ophtho, 1 anesthesia and 1 rad onc. We also get to know the faculty well (as TAs) and some have held leadership positions.
I recall wishing I had gotten off the waitlist and being envious of the T1s with whom I took Gross Anatomy during the Fall of my ACP year. I didn't want to be in limbo for another year but in retrospect, I would have done it exactly the same way it happened. It was an extra year, but it was more than worth it.
Good luck to all those applying, and feel free to ask any questions you may have. I'll do my best to respond promptly.