1) Class size varies by time and course. Thus, I cannot really give a "typical" example. Evidence, Business Orgs, Oil & Gas, etc. (bar courses) tend to be larger classes (60+). Some classes (mostly practice skill courses) are small, 10-20 students.
2) The answer varies based on class size and professor. Class size matters due to the curve (smaller classes have higher curves, making it harder to get below a C). Professor preference for curving matters to (some professors give only a few As, meaning they can give few Cs or lower). The general answer is "very few" people - less than a handful, even in a large class, will generally receive less than a C. Student services provides the grade distribution for each course/professor.
3) Business Organizations with Moll. Secured Financing with Moll. Most of the Bar courses are sufficiently large and offered enough for space not to matter much.