Welcome to our Forum.  Thanks for your questions.  I'll do my best to answer them.  First some generalizations and let me congratulate you on your commitment to safe, condom protected sex.  Condoms remain the best way to reduce risk for STIs including HIV and are highly effective when used correctly and consistently.  As another generalization, vaginal sex is a higher risk exposure than receipt of oral sex: there are no documented cases in which HIV has been acquired from receipt of oral sex, obviously that is not the case for vaginal exposures.  Further, for other STIs, the biological efficiency (i.e. likelihood of acquiring infection) is higher for unprotected vaginal exposures than for receipt of unprotected oral sex so if you were going to only use condoms for one sort of exposure, you chose the right site to protect.  With this as background, I'll now answer your specific questions:

 1. Based on the many sexual encounters described above, do I need an HIV test on scientific/medical grounds?

Given your history, your risk for HIV is low.  Most CSWs do not have HIV and since your penile-vaginal exposures were condom protected, your risk of HIV if virtually zero.  OTOH, we believe that all sexually active persons who have new or multiple partners should probably be tested for STIs, including HIV once yearly as a matter of good sexual health practice.  Thus as a generalization, I would suggest STI, including HIV testing but would also expect the results to show that you have not been infected.

Se above, virtually zero.

Best practice would be to have the STI screening I mentioned above but, from what you say, there is little risk that you are infected or need to worry.

I hope that this information is helpful.  EWH

1. What is meant by "virtually zero"? 

2. To get clarification on the third answer, I could have unprotected sex with a new dating partner now, but should make time to get tested just for best health practices? 

1.  There is no such thing as truly zero as technically things could change tomorrow.  Virtually zero is the correct term.  Be reassured-that is as low a risk as possible short of celibacy.  

2.  You have  accurately repeated my response.  EWH

I am going on a date tonight with my new girlfriend. I just want to be clear that I can have unprotected vaginal sex with her tonight without worrying about me infecting her with HIV? 

If I were you, given the information you have provided, I would not be worried about infecting her by having unprotected intercourse with her.

Hope this helps.  As you know, now, with this 3rd response, this thread will now be closed.   EWH.