Recurring subscription / Coupon with one time application / Price on subs. form

Hi Tuan,
I have several recurring subscriptions, for 6 or 12 months.
I created a coupon for 25% discount on these subscriptions, applicable for the 1st payment only.

When a user subscribe, I would like the price to be very clear :

First payment :
Discount amount :
Tax amount:
Discount gross amount:

Next payments :
Regular amount:
Tax amount :
Regular gross amount: 

For the moment, I only have little notification in the payment terms box with the first discount amount, and then regular price in the big boxes (see screenshot).
Could it be more clear with the discount ?
Can you tell me if this is possible with an override ?

Another question : could it be possible to automatically fill a coupon field with a coupon code, by default ?

Regards,
Catherine