I really thought I had answered this yesterday, but apparently it didn't post. My apologies.
1. Am I at risk of any STD including HIV from this incidence? ( please ***** the fact that there were some of her vaginal secretions on my urethra and foreskin)
No risk for gonorrhea, chlamydia, NGU or HIV from this. You really need penetration for those. There is a chance that you could have gotten herpes, syphilis or HPV from this.
2. Can there be a chance of me contracting HIV or other STD while she rigorously rubbed her Vagina directly to my Scortum ?(please assess the fact that i very had a micro cut on scortum skin 6 hours before the activity)
See #1. If she was rubbing you rigorously, then there may have been enough friction for herpes, syphilis and HPV to transmit.
3. Has there been any reported case of HIV acquired from act of frottage only?
No.
4. How long should it take for symptoms (if any) of a STD to show after this incidence?
Herpes symptoms usually appear within 2-20 days, with an average of 4 days.
Syphilis sores, called chancres, usually appear within 10-90 days, though the average is 21 days.
HPV, if you get symptoms (many strains don't give visible symptoms) can take a few months.
5. Should I engage in sexual activity with my girlfriend after this?
That's up to you. HPV is very, very common, and if you've had sex with more than 1 partner, or your girlfriend has, chances are you've had HPV. There is no test for HPV for men.
Syphilis is less common, though there is a chance you'd get it. You can test for that at 6 weeks, and then again at 12 weeks. Most people are positive by 6 weeks.
Herpes is common, but not nearly as much as HPV. You can test for this now, to see if you already have it, and then again at 16 weeks.