And, some motherly advice...change your shorts every day, not just once every 3 weeks. You will be banned an outcast if the ladies find that out sweetie.
If you do have herpes you are lucky to have a case of it that you don't even recognize! Try having 10 outbreaks a year that cause blisters, it's not very fun so even if you are positive you are very lucky! Go get the test and quit messing around..
You answered your own question: Have a blood test for herpes. All the rest is icing on the cake, with no important bearing on whether or not you actually are infected. The symptoms you describe don't sound like herpes, but that doesn't mean you aren't infected.
1) Lots of things can cause rashes in the genital area of women. Herpes is the most common cause of genital sores, but other things are possible. You don't provide nearly enough information for me (or you) to judge the accuracy of your partner's diagnosis. But the odds are she wouldn't have called you if she and her provider were not pretty sure about the diagnosis.
2, 3, 4) The answer to all 3 quesions is that you need a blood test for HSV-2. Don't try to find what herpes looks like. If the blood test is negative, you will know you don't have it. If it is positive, then you can worry about what sort of lesions to look for.
If you haven't done so, read the herpes information in the link STD Quick Facts and Articles on the STD forum home page. Also visit the American Social Health Association (www.ashastd.org) and the Westover Heights Clinic (www.westoverheights.com) for excellent herpes information; one of those sites may have pictures, I'm not sure.
Good luck-- HHH, MD