Free Shipping Coupon Code Not Working

I have a couple issues.

One - I can't get the free shipping coupon code to work. I'm using Powerstore v2 - and eCart. I have coupon codes setup - and with the test coupon "WebAssist" (gives 10% off subtotal price) - that works fine in the shopping cart - you can see the 10% discounted in the cart view. I created another discount of "SHIP123" - and it doesn't work. Probably because I don't know what the calculation should be. I'm using UPS and item weight to calculate the shipping cost. What should the discount code calculation be? I tried a few things and it still shows a shipping cost when I go through the purchase process.

My other problem is that - since it's a shipping discount code - and it doesn't know what the shipping amount is until you input your ship to address - the customer (and me during testing) can't tell if there is any coupon code being attributed when you input the coupon code.

So first - how do I get it to work, and second - how can I get it to verify this on the cart view if/when it does work?

Thank you so much.