At Haneda, it's the same platform.
But if that specific station is the starting station, there might be different platforms.
Price is the same for different genre of trains on the same line. They charge by distance.

Normally 1 hour to clear immigration.
By the time u come out, ur luggage should be off the carousel waiting for u.
U can still make it.

Nope. Both Haneda & Narita are busy airports.
When I'm talking about 1 hour, there're 10 counters operating, at least.
Because the immigration officers will query individual. So please be prepare to answer their questions, like where you will stay, what sort of accomodation is it, etc.

Check if ur card support PLUS or CIRRUS?

I did withdrawal in Japan on 3 occasions, using Maybank ATM card. All of them at Citibank. Max withdrawal amount per transaction JPY150k.