In short - no, it doesn't have to be a bad idea and a relationship disaster to date a working girl.
It's worthwhile to perhaps see the matter from a more nuanced perspective for once. I appreciate that some individuals on here will never ever get past their own ego and rigid stereotypical thinking, clinging to their belief that 'no sensible man' could ever consider it. Why do such people continue to punt when continuously looking down on the WGs they punt with, as if they are somehow lesser people, remains a mystery. Reminder: the WGs are people with the same relationship needs and capabilities, just like you.
To those who are willing to open their mind, a few facts:
First (most important), this is only a job. She takes a booking, gets paid for it, provides a service, client leaves and she forgets about him. Next. That's all. He doesn't get anything else from her apart from a performance of an agreed activity for am agreed fee. Believe it or not, for vast majority of working girls this is only a means to pay their bills and achieve whatever financial goals they have. The WG "uses" punters to the same extend the punters are "using" her, only the type of gratification is different.
Second, she chose YOU. Among all the guys she meets and who pay her money, it is YOU that she comes back to at the end of the day. It's YOU who is the man in her life, not punters. There is no emotional attachment or loyalty to the punters and IMHO, loyalty is far more than just physical fidelity.
Third, she likely makes more than you. I cannot see how this is a problem unless the man has a really fragile ego and cannot get over it. If anything, this is a good thing since you know that she is unlikely to be with you for material reasons. It doesn't have to mean you're just a wallet and that she will expect you to pay for everything and spoil her with designer handbags. She can easily do this herself. The WG is likely in this relationship for reasons unrelated to money. Tell me how many "normal" "self-respecting" vanilla girls get into a relationship and don't expect the man to pay for everything and eventually sustain her, just because she exists.
Fourth - if the working girl actually tells you about what she does, that's great. The earlier she tells you the better. This means two major things - first she respects you enough to tell you so you can make an informed choice and don't waste time if you cannot accept it and second - she wants to build a relationship on an honest foundation, without tricks and bullshit.
Fifth - you chose her and she knows not many would be sensible enough to get past the stereotypes, their own ego and knee-jerk "FUCK NO" type of responses. This can actually make her appreciate you more and increase her loyalty to you.
Sixth: The whole idea that she would be "too tired to have sex with you after doing all those guys" is laughable. So if she was a primary school teacher sitting with someone else's kids all day, does it mean she would be too tired to play with her own kids when she gets home? Wrong again. Sex with punters vs sex with a partner -> inconsequential paid performance with a stranger versus genuine intimacy with someone she is actually attracted to. Can't compare apples and oranges.
Seventh: one of the comments above that "they are all batshit crazy" made me laugh. Many escorts that I am friends with have their heads seriously screwed on and treat this job only as a financial instrument for other things, be it funding their education, supplement existing income or setting up their own business. Selling sex is only that, selling sex and it doesn't tell you anything else about the woman.
I hope this clarifies.
