Welcome to the Forum. the exposure you describe is associated with little risk for STD of any sort. Condom protected sex is safe sex. Kissing and "sucking" does not carry risk. In answer to your specific questions:
1. Shaving 2 days before your exposure does not change your risk. Syphilis and herpes are most likely to occur if you were in contact with a lesion,. If you did not see a lesion you have little risk. Furthermore, syphilis is very rare and therefore not a concern. As for HSV, if you do not develop lesions in the 4-10 days following your exposure, you really do not need to worry about herpes either.
2. Zero
3. Persons with syphilis or herpes are at about a 3-fold increased risk of getting HIV if exposed. You are not likely to have either infection and are unlikely to have been exposed..
4. Miniscule
5. There is nothing in the history you provide to suggest that you need STD testing. If you wish to be screened for infections you might have had before the exposure you describe, you would want to be tested for gonorrhea, chlamydia, NGU, and HIV.
Hope this helps. Try not to worry. You really are not at risk from this exposure. EWH