Can a heterosexual male who has been abstinent for 4 years, never had any symptoms of an sti, and had few previous partners, still infect a future partner with hpv? how likely or unlikely is that? what are the ramifications?

While HPV can gradually be non-infectious, it may take longer for your immune system to remove the infectious component, and transmission is possible. A "future partner" should be informed, but only a few types of HPV are causative of potential cervical cancer in a female, and regular pap smears can test for their presence, and treatment instituted.