Is this an example of soliciting a prostitute ? And beyond reasonable doubt? Law questions?

Beyond a reasonable doubt is required for a finding of guilt within the legal system. To have the solicitation of a prostitute, you must first describe the sex act and you must then negotiate a price. Just asking a woman if oral is her thing is just inquiring about her sexual preferences. Until you offer her money for the act, or she says she does this act for a specific price you have no offense, so reasonable doubt is not an issue..