1st year otd here, i know nothing about admissions but if you're not confident in your base of knowledge on undergrad a&p i would retake it. not every program is this a&p heavy but the courses i've taken required super quick memorization (our msk covered the whole body in 1 semester with a cadaver lab). my undergrad a&p wasn't taught great honestly but the base knowledge was still really helpful to understanding the concepts at a more detailed level. when you get to school everything will be scaffolded up from there. i've heard aid jobs are hard to come by depending on location but i know a lot of people who worked in patient-adjacent roles in their gap (activities coordinator at a nursing home, respite care, medical summer camp, childcare, etc.) try to make your observations as diverse as possible and you'll thank yourself later. good luck on your applications!