You had no risk of getting genital herpes of either type (1 or 2) if no one performed oral sex on you, or you didn't have any kind of genital to genital contact with either man.
You could get oral hsv1 from kissing. Do you know if you have that already? 90% of those that have it never get any symptoms, so testing is the only way to know, and most STD testing doesn't include herpes blood testing.
1) What is the probability that I’ve contracted an STD, more specifically herpes?
2) How well does hand sanitizer ( ethyl alcohol 70%) kill herpes effectively?
This hasn't been studied on the body. It's not ever meant to be used on the mouth or genitals, and I wouldn't be a bit surprised if this caused your sore throat and cough. If you still have that, you need to be seen by a doctor.
3) Can herpes be transmitted through water?
No, but I'm confused as to what water you were exposed to? Well, I mean, if you had sex in a pool, you could get herpes if your partner has it, but if you mean you get in a hot tub with someone who has herpes, but sit on the other side of the tub from them, you won't get it.
4) Based on how I described my sexual experience, would it count as a high or low risk activity?
No risk. I'm including links at the bottom to explain why.
5) Theoretically, what would the probability of contracting herpes from direct skin-to-skin contact with someone who is shedding/ has an outbreak? (Worse case scenario)
The only skin to skin you had was mouth to mouth, so there is a possibility of getting oral herpes type 1, if you don't already have it. When we talk about skin to skin contact in regards to herpes, we mean mouth to mouth, mouth to genital, genital to genital, anal to genital. You didn't have any of that. People with herpes are only infectious from the location of their infection. If they have genital herpes, they are only infectious from their genitals, not their hands, their arms, their eyes, etc.
Why mutual masturbation (hand jobs) is never a risk:
Here are some posts from our experts (when we had them) that may help -
- read this thread thoroughly. There is an excellent explanation about why certain activities are not risks, and why others are.