What grade ptosis do I have and will thermibreast work for me? (photo)

You actually do not have much breast ptosis (sagging), and a ThermiBreast would be an excellent choice for you. This will raise your areola/ nipple about an inch. 
The ThermiBreast will also tighten your entire breast if the ThermiBreast is done circumferentially.
There should be no visible scar following the procedure, and it can be done under local anesthesia. I do use nitrous oxide for patients having this procedure, which makes it much more pleasant and comfortable. There is generally a day or two recovery.
Thank you for your interesting question, and best of luck to you.

There are some mathematical measurement parameters that can divide the degree of ptosis. From the photographs I don't think this is an issue. Using heat to tighten the breast is embryonal and something I personally would not recommend at this point in time.

You have pseudoptosis- your nipples are at the fold level with some tissue below. Thermi Breast may tighten enough without large scars. Another option is breast implants.An exam and consultation with a plastic surgeon who performs these procedures is recommended to confirm you are a candidate as well as discuss your options and expectations.