i wouldn't worry too much about taking the a&p lab online. there are some great software programs and high quality textbooks that can get the job done. and you seem satisfied with micro online.
but, regardless of where or how you take a&p it's a class that takes most people a lot of time and effort to master. anatomy requires a lot of memorization and some of the physiology concepts require extra time to truly understand.
a history course is likely going to require a lot of reading, and depending on your abilities math might take up a lot of time with problem sets. four classes at most schools is a full time course load and if you’re working full time, that’s a pretty heavy schedule.
if you decide to go for it, review each course syllabus carefully on the first day of classes. check to see how much reading and homework is required, and see what the timing is for the exams and assignments. you know your skills and abilities best so only you know if you can handle it.
dropping a class and taking it later, even if it means delaying your application is probably easier than trying to overcome a bad grade. good luck whatever you decide!
on a side note, i'd actually hesitate the most on taking public speaking online. while i've seen some really good virtual science labs, i'm not sure how you could mimic getting up in front of a group and speaking.