HELP! How to create custom by-phone orders from backend?

Hi,

If I have customers calling in to order by phone, I need to have the option of creating an order at the backend in my office. Assuming the customer has already registered an account on my store,

(1) Any recommended extension to have this store-owner created order entry? I can't use the workaround where I simply add the cart what my customer wants as I can't log into my customer's account.

(2) Can this order entry able to query and auto-fill customer's details into the order form AND register as a sale in the OC backend with a discounted price that has not been entered into the Products -> Discount tab?

Reason is when customers want to order by phone, they're usually asking for large orders, and will want to have a special price. I won't have to time to create that special price via Products -> Discount when I'm negotiating on the phone.

(3) Once the order is made, I'll need this order to be processed into an Invoice and an email sent to the customer with a special payment link where they will click to make their payment.

Please advise if this is already possible in 2.0.3.1, or any extensions you'll recommend.

Thanks!

I just put them in from the front end of the store. If they have an account, I first go to admin section and login as them, then just place the order as normal from the front. Also gives me a chance to test to make sure everything is working or if I need to update any info.