Statutory rape is still a crime even when it's undertaken completely consensually. Rape doesn't necessarily indicate violence. The world is finally coming around to realizing that it very often involves coercion or some sort, of which the OP was simply one example.

I'm not diving into your hypotheticals because failing to make good on your promises or keeping information back is a slightly different set of circumstances than getting someone to have sex with you for the first time through fraud. "Taking advantage of someone" is not quite the same as committing fraud through deception either.

All forms of nonconsensual sexual assault may be considered rape and are in most jurisdictions. By more broad legal definition, one must understand the nature of any transaction in order to be able to agree to it. A judge would need to instruct the jury on the legal definitions that are relevant to the particular case in that jurisdiction. Whether or not it would legally be considered non-consensual sex due to fraudulent deception would depend on the specifics of each case. My point is, in certain circumstances that could well happen because it's not less fraudulent to obtain access to someone's body through deception than it is to obtain access to someone's possessions through deception.

Here's a good in-depth legal analysis :

https://digitalcommons.law.buffalo.edu/cgi/viewcontent.cgi?article=1341&context=journal_articles