I did a search on this but I couldn't find out exactly what I was looking for. I'm ashamed to say that I don't know much about degreasers. I know what they do basically but still I don't get it.
Can someone answer these questions for me please?

1) When should I use a degreaser? Are they too harsh to use every week when washing?

2) Aren't degreasers just a strong cleaner like APC? Is there a difference?

3) I see a lot people spray the lower portions of their car and the wheels with degreasers.
Won't this compromise the wax in those areas?

4) If degreasers don't remove wax then why not just use regular shampoo?

Thanks.