Taking 3 AP sciences concurrently is a disaster waiting to happen. AP Bio and AP Chem are both time consuming by themselves, but they also both have very extensive lab requirement. So in addition to the “normal” AP homework, you will also spend considerable time writing lab reports. On top of that, both these courses usually have double periods and/or meet before or after school to perform the labs.
In terms of Physics C vs. Chem, it’s really a personal choice. One is not viewed more favorably than the other.