A lot of this depends on how "light" the touching and rubbing was.
There is no risk for HIV, gonorrhea, chlamydia, and NGU. Those require his fluids to enter your urethra. Without penetration (oral, vaginal, anal), that doesn't happen.
In theory, rubbing and grinding without clothing can transmit herpes, HPV and syphilis. In reality, this would take some pretty heavy grinding, as friction is needed. This is why I say that it depends on how light the rubbing was. Think of the friction achieved by having actual intercourse - that's usually the kind of friction needed.
To transmit syphilis, an actual sore needs to be present. Symptoms do not need to be present to transmit herpes or HPV.
Without knowing how much rubbing there was, it's hard to say what kind of risk level you had, but it doesn't sound like a lot.
Assuming you were infected (and again, it doesn't sound likely, but I'm going with your question #3), you probably aren't "immediately" contagious, as in within seconds, but you would be shortly after, say within a day.
There is no test for men and HPV. It can take several weeks to several months to show symptoms, and some strains never do. If you haven't been vaccinated for HPV, you should talk to your doctor about that.
You can test for herpes at 12 weeks, but if you don't have symptoms, I'd caution you about this. There is a decent chance of getting a false positive on the hsv2 IgG herpes test (the test you want), and it can take weeks, a lot of money and even more stress to figure that out. Also, a lot of countries - Canada, the UK and others in Europe - don't like doing the herpes blood test, for this reason, and it will be hard to get.
A syphilis test will be accurate at 6 weeks.
Unless you had some heavy grinding, which it doesn't sound like, I wouldn't worry.