Hi Hollie,
I'm so sorry to hear about your husbands medical problems. I just want to refer you to a really useful website that you can use for a resource. It's www.oralcancerfoundation.org There are SOOO many people there that can answer ANY question you may have. There is also a really good search feature that you can use to just look up your question topics.
My dad was diagnosed with SSC in June and that website has been a huge help for me.
In response to a couple of your questions: Yes, there is a correlation between HPV and oral/head&neck cancers. Generally, HPV positive patients respond better to treatment. Usually though, the treatment plan will not change based on whether or not a patient has HPV or not, which is why some doctors don't seem to think it's important to find out about.
Also, try not to get too worried about statistics. Just believe that your husband will beat it. LOTS of people do! And your hubby has youth on his side.
Please let me know if I can answer anything else.
Stephanie