The topic of HPV and genital warts is a complex one. I will try to provide some facts. For addition information on this most common of STDs, I would suggest search for other HPV- and wart-related Q&A on this site, as well seeking addition information on sites such as the American Social health Association web-site (disclosure, Dr. Handsfield and I are both on the Board of ASHA)..
HPV is the most commonly acquired STD. Over 85% of sexually active women will have HPV infection at some time in their lives. Less is known about HPV in men than in women. In some people HPV will cause genital warts, in others it will not cause warts but in women may lead to changes in PAP smears. In nearly everyone who gets HPV, warts or otherwise, the infections will resolve by themselves without therapy in 8-10 months. In a very small minority of women, HPV infection can persist and lead to the pre-cancerous lesions that PAP smears detect and which can then be treated. With this as background, lets go on to your specific questions, realizing that the questions you ask are complex and beyond the scope of this site. I will provide you with some initial information but cannot answer all of your questions:
1. Warts are caused by HPV. If you have warts, you have HPV. At the same time, as mentioned above, nearly everyone gets HPV at some point. As a result the issues of notification of partners and partner management are more complex and the answers less clear than for many other STDS.
2. You probably got your infection form someone you had sex with in the last year or so. A good approach for many people is to indicate to your partner your surprise that you discovered you have warts and suggest they get checked. Practically speaking, there is no data to indicate that you need to change your sexual practices with a partner you have been intimate with for the past several years. At the same time, should you wish to take precautions, condoms do markedly reduce risk of HPV infection.
3. HPV infections tend to limit themselves to specific types of epithelium (skin). thus it is unlikely that your partner got infected from performing oral sex on you. If it did, the probability of further consequences is small.
4. The HPV that causes visible warts rarely causes cancer. Most persons with HPV will not get cancer.
5. The issues of partner notification is a tough one. See above for comments. Also, check out the web sites for information.
Hope this helps to get started. Learn from the web sites I've suggested. Take care. EWH