Welcome to the forum.
Oral sex is safe sex. Not completely risk free, but with little risk compared with unprotected vaginal or anal sex.
First set of circumstances:
1) Ejaculation in a body cavity increases risk for the recipient, but has no bearing on STD/HIV risk for the ejaculator. (Obviously. I don't understand wny so mean people seem not to get this.)
2) Can't hurt, but I doubt it helps much.
3) Urinating after sex is time-honored to help prevent STDs, but probably makes little or no difference.
4) Probably irrelevant. Most self-observed lymph node enlargements cannot be confirmed by health professionals.
5) Probably makes no difference.
History
1) See no. 4 above. Unless and until lymph node enlargements are confirmed by professional evaluation, I would ignore them.
2) Elevated or variable WBC counts are irrelevant in evaluating patients for STD.
Questions and Comments
1) Receiving oral sex carries little risk for STDs. See this thread from earlier today (as well as almost daily questions about it):
http://www.medhelp.org/posts/STDs/Negative-std-test/show/1880931
2) Augmentin is not a recommended treatment for any STD that might be acquired by oral sex. However, it probably would prevent or abort gonorrhea and for sure would prevent syphilis.
3) See above. This has never been carefully studied, but probably makes little difference. One study actually shows the opposite, that washing with soap and water after sex increases the risk of HIV. But I doubt that study was valid.
The standard advice about oral sex, as discussed in the thread linked above, is to not worry about it if symptoms of STD don't appear.
Regards-- HHH, MD