For the record, I did not say cilantro pesto would be too strong, I said a pesto made with cilantro as the only herb would be very strong, and would overpower the shrimp. Worth adding now that cilantro stems are especially strong flavored. I recommended adding some parsley and a little bit of mint to tone down the cilantro and add some complexity. Watercress instead of parsley would also work well.
FWIW, cilantro, parsley, onion, mint and powdered hibiscus (or mango, aka amchur) -- without oil, nuts or cheese -- is classic Indian "mint chutney." It's a great and very adaptable flavor profile. Using the same herbs in slightly different proportions with the addition of a pesto's garlic, nuts and oil would work very well. I'd keep the cheese away from shrimp, and might go shallots over garlic, but that's me.
I'm not sure about the other 9 people -- who should probably quit smoking -- but I can taste the difference between basil and cilantro pestos. If the flavors were masked by things like too much garlic and cheese that might interfere, but I doubt it. Cilantro is very distinctive.
You're using the term "pan sauce" in a non-standard way; it doesn't simply mean "cooked in a pan." The foundation of a pan sauce is a fond deglaze. Your butter mounted tequila/stock reduction is more of a jus.
If I understand your saucing idea correctly, I think you have it backwards. Prepare the reduction in a large skillet, without butter. Add the barely cooked pasta to it along with a little pasta water to tighten the sauce, and toss over a very hot flame until the pasta absorbs some flavor and the sauce structures. Plate the pasta with just barely enough of sauce -- pasta should not be drowning. Plate the separately cooked shrimp on top of the pasta. Garnish with a few drops of pesto here and there if you like. Pass the remaining pesto for the guests to either fortify the sauce or use as a dip.
It really sounds like you don't want advice as much as validation. Because I wouldn't present a straight cilantro pesto or use butter in the reduction, doesn't mean you shouldn't. Go for it.