marketpress cart & checkout customization

I need to customize my maketpress cart and checkout process.

Since i am selling appontments with A+ I need to:

1: Remove the quantity field from the "review cart". This field is not applicable.

2: Remove the "Have a user account" section as no one will log in to purchase.

Since I am not shipping anything I would like to remove the whole "shipping" step from the checkout process. I have set shipping method to "no shipping" in the store settings but it still appears in the checkout process.

How can I do this?