This is coming from someone who had the same anxiety over HPV as you have: it's impossible to know unless you develop genital warts. If you don't, you just don't. HPV is not like HIV, which inevitably attacks the system significantly. HPV is quite common and most of the time, the body clears the virus by itself a la chickenpox.
You will drive yourself mad worrying about HPV. I understand your concern for your health but you should consult with your dcotor and develop a strategy then.
Once again, don't stress yourself.
Relax. A majority of people who are sexually active will get HPV at some point in their lives. As Dr. Handsfield says on the Expert's forum, "It's not desirable, but it's normal." Your former partner probably became aware of her infection through an abnormal PAP smear or the presence of genital warts. However, most people with HPV infections are asymptomatic and the infection generally "clears" within 8-10 months (not everybody, but a good majority will clear within 2 years).
To answer your quesitons directly:
1) No, the only way to diagnose HPV in males right now is the presence of genital warts. If you have HPV, it will probably never cause you any problems.
2) Condoms aren't 100% effective, but they are good. HPV is acquired through skin-to-skin contact, and the condom does not cover the enitre genital region. There's some chance that you were infected, but the condom usage reduces this risk significantly.
You will probably never know if you contracted the HPV infection from your former partner. But in reality, this should really not be such a major concern to your new partner. Most people have been exposed to HPV, but they just don't know it. Unless you notice genital warts, I would not let this interfere too drastically with your sex life. Condoms will provide extra protection for you and your partner. Also, it's important that your partner get yearly PAP smears. If she has been sexually active, it's quite possible that she has been exposed to HPV herself (but since most people are asymptomatic, she probably didn't even know it). I hope this helps.
Good luck,
Em