1. From my experience, that sounds pretty normal. If you caught it at the time of the rash, that's secondary, not tertiary stage (by definition). After that it can go underground for years (sometimes decades) before the slow damage it causes to your body allows it to emerge as tertiary syphilis.
An explanation of the "syphilis count" numbers: The RPR (rapid plasma reagin) test is *not* a specific test for the syphilis organism. It is a test for antibodies to a substance found naturally inside the human body's cells, that is released when they are damaged by the syphilis organism. Even after the syphilis organism is gone from the body, it can take a long time for these antibodies to drop back to the "unreactive" level, and sometimes they never do so at all. There's a more specific test for the organism itself, and if you get a reactive test on the RPR, they use the specific one to confirm that you actually have active syphilis.
2. Correct, and besides your body can develop an allergy to penicillin, so it's good to avoid using it unless you really need it. If you're allergic, you can't use it when you might really need it!
3. I get tested regularly and treated when necessary. The main impact on my personal life is that sometimes my playmates are disturbed or pissed off if they get the news that they've been exposed to something. That's annoying, but I don't consider it my problem - they're grown up people and they know (or should know) the risks. I never pretend to be an angel. It has no impact on my professional life (none of anyone's business in that arena).