Custom Discount fields

Hi there,

I would like to know if this plug-in has the ability to add a checkbox, if checked, provides in the following order:

1. The ability to add a checkbox, if checked, provides in the following order:
a) 15% off the items in the cart (this should also work for items added later)
b) Adds $25 to the cart (this charge will not be discounted by point 1 – hence the order of sequence)

2. Allow multiple of feature one above per checkout/cart – example, I have a membership checkbox and an auto-delivery checkbox, both will apply 15% to the items in the cart. Hence if you check both, you will get a total of 30%.

3. If any of the checkboxes above are checked, once the purchase is made, the user is automatically put into corresponding WP roles (memberships) so that next time they purchase, they will automatically get the 30% off if they checked both checkboxes.

I know number 3 would not be possible with this plug-in.

Thanks