No. Trichomonas is not known to be carried in the oral cavity, and not known to be transmitted by oral sex. This hasn't been carefully researched, so conceivably it is possible. But in my 40 years in the STD business, I have never seen a patient with trich whose only apparent exposure was oral-genital contact. In general, oral sex is much lower risk than vaginal or anal sex for all STDs.
Yes. Yes trichomoniasis can be transmitted by oral sex. Condoms or dental dam should always be used when performing or receiving oral sex. Please be safe.