Welcome back to the Forum. While you state that you know that HPV is not a big deal, your pseudonym, your questions tell me otherwise and suggest that you are feeling guilty about your exposure and that you are now both repeatedly examining yourself and searching the internet about STDs. This is not a good idea, as your reference to an over 3 year old response to a question suggests. In recent years we have learned that warts do not appear within days or weeks of exposure and, on average, take 6 months to become apparent. What you describe is most likely something normal or the result of repeated self-examination. If you wish to get it sorted out, have a knowledgeable clinician take a look (and do not allow them to treat it "just in case" since this will likely just fuel your paranoia.
As for your specific questions:
1 After exposure, how soon can a wart can show up. Many of your posts say it takes months, but some of them say that it can take weeks
http://www.medhelp.org/posts/STDs/Warts/show/977757 ; Is this possibly something NEW? Or can i confidently assume that both me and my girlfriend were exposed prior to my indiscretion?
Whatever it is, this lesion is NOT a wart from your recent mis-step.
2 Is it possible that this has been dormant in me for a decade? Wouldnt i have cleared it from my system?
See above, It is most unlikely that if this is a wart, it appeared recently.
3 if i had this for 10 years but never had a wart, would my girlfriend still have been exposed?
Not sure I understand this question.
4 Is genital-to-oral transmission possible/probable? Should i prevent my gf from perform oral sex?
No, see above. Your receipt of oral sex did not cause this and this is not a reason to not have oral sex with your GF.
5 Can you direct me to resources that confirm/discuss that warts can be dormant for a long time or that they take longer than 2 weeks to show up?
See above. Some dermatologists can do this for you.
6 if i have it treated will it be obvious? Will there be a scar/blood/increased visibility?
No, it will not be particularly obvious but I think you should find out what this is before it occurs.
7 if i do the vinegar test and this turns white, how long will it stay white for? dont want gf to see it if its white
The effect of the vinegar test is brief and disappears when the vinegar is washed off however the vinegar test is now appreciated to be a poor test with many false positive results.
8 Will it grow/spread?
Neither you nor I know what it is. That's the first step. Growth is unlikely
I hope this helps. EWH