Whirlfloc and dry hopping

Ok so these are 2 separate questions related to my last brew (my first 5 gallon batch).

Here's what I'm working with, an SNPA clone I found on here. At least what I could find that was partial mash:

4 lbs American 2 row
1 lb Crystal 40
6 oz Carapils
3 lbs light DME

I mashed all the grains at 148-152 for 60 mins (BIAB) and ended up with a 4 gallon boil (too much sparge water I think). I added 1/2 the DME at the beginning of the boil and the other half at 15 minutes.

1 oz Perle 60 minutes
1 oz cascade 15 minutes
1 whirlfloc tab at 10 minutes
.75 oz cascade flameout

Topped off to 5 gallons, OG 1.046

Pitched a WY1056 smack pack, no starter. It's now fermenting quite nicely 48 hours in.

Question #1: I didn't really understand what whirlfloc was supposed to do. I thought it was supposed to help everything clear in the fermentor but later learned it helps clear in the boil. After struggling to get my wort in my carboy (too small of a funnel, didn't have a good auto-siphon, lesson learned) I ended up just saying "F it" and dumped everything in there. Am I going to get any benefit out of the whirlfloc or am I just at the mercy of letting everything settle?

Question #2: My recipe also called for a week of dry hopping of 1 oz of whole cascade. Since I've got all that hop in the fermentor, should I back off on this or eliminate it entirely? I would personally love all the hop I can get, but I want to make something fairly "safe" so I can get my friends and coworkers hooked before getting too adventurous. Any thoughts?

You will still benefit from the whirfloc I only use a half tab per 5 gallons. I would still dry hop even though not a fan of cascade as a dry hop.