Yes, you are overthinking it.

You've booked some time with a service provider who is asking to gain insight as to just what type of service your would prefer.

Go to a barber (yeah, I'm a dinosaur...I don't go to a "stylist") and just tell them "whatever" -- will you likely be happy with the result?

It's your time, it's your money and they're your balls.  

She isn't a mind reader, so you should really think seriously about what you like (seems you've got that part down) AND then rehearse just what you want to say.

She's heard it all before and will appreciate someone who knows what they want...and can clearly ask for it.

Buena suerte!

My knee-jerk response to you was going to be "just tell her, she's an escort, It's easy", but then I reflected on it and I agree with you: it can be awkward to blurt it out. There's even an element of rejection in the escort/client world just as there is in the civvie dating world. It's not always easy to bare one's soul about sexual likes, desires, kinks, fetishes and fantasies.

Here's a possible work-around from my own playbook. Before she can ask me what I want, I beat her to the punch by asking her: "What do you allow and what do you not allow?" Based on her answer, I tailor my next comment, for instance, of she names something that I want it like as part of what she allows, them I'm in. If she names something that I want it like as part of what she doesn't allow, them I know it's off the table. One thing I never do is attempt to negotiate or bargain. If she only does CBJ instead of BBBJ, I'm not going to try and convince her otherwise.  

If and when she asks me first to tell her what I want or like, I'm at the point now that I just say it. Both my time and money are precious and limited, so I don't want to put up with disappointing sessions, regrets, or buyer's remorse.  If I don't speak up ahead of time, only to find out later that it might have gone on my favor, the could-haves and should-haves are on me. Of course, it doesn't always work, but that's life. I won't lie and say that every escort has been great about my desires or kinks, because they're all human beings, and people have their own opinions about things. Some escorts politely decline something or simply say they're not into it, others act as if you've just suggested animal sacrifice or worse.  

When it works, it works. I once had a fantastic session with an escort who blew my mind in how accommodating and eager she was, she complied with my clothing request, she acted her part in a role-playing scenario I had, she stayed in character for the whole hour, gave great service over and above my expectations. After we finished, had showered and were getting dressed to leave, we were chatting, and I made a passing remark about something else that I like In bed and would have wanted her to do. It's something out of the ordinary, a little daring and bold, and not many people are into it, so I hadn't asked for it. She looked at me and said, "Why didn't you tell me you wanted that? I would have done it gladly."  Doh! What an idiot I was, lol. I learned from that tv at it doesn't hurt to ask.

Don't worry about being forward. One never knows what another person is willing to do. The last point I'll make is to be glad you're being asked what you like. Nobody is a mindreader, so if a woman who is about to have sex with you gives you a chance to call some of the shots, tell it like it is. Open communication between people who are having sex with each other is one of the best ways toward mutual satisfaction.

What Do You Like.

I answer by saying, "I'll Let You Know As We Go Along ". Being upfront with specifics does seem harsh on a first meeting.

Yeah, you’re overthinking.  

You have researched her, right? At the very least you should know it’s not out of the question, or that she’s gotten good reviews for oral.

No, you don’t have to say “I like having my balls sucked.” There’s an art to being subtle.

You can say something about appreciating oral skills, all over. You can say, My balls would really appreciate some extra attention. I’d really enjoy that if you’re game. Say it with a smile and confidence so she knows that her skills will be rewarded. Unless that’s off the menu, the odds are that she’ll spend an inordinate amount of time there. If she does, please put it in a review so others who get off on the same thing (raises hand) will know this is a lady to visit with.

Sometimes a cigar is just a cigar.  Your provider wants to give you the best service, and is being direct about it.  Your best bet is to answer her directly without being too crass.  For instance, say "I like to have my balls stimulated", rather than "I like it when a woman licks and sucks on my balls"; most women will get the hint.  Although for a PSE session, the latter is totally fine.  If your request goes against her rules or comfort level, she'll tell you; if not, she'll give you what you asked for.  And honestly, if you're seeing a sex worker, it should be a given that you're comfortable verbalizing your sexual desires.