Would Paul Heyman be a good mouthpiece for Nakamura
 

Since Heyman seems to work best for guys who don't cut promos well -- would he be a good mouthpiece for, as Michael Cole calls him, "Shin" Nakamura?

Not sure. What Nakamura does now seems to work for him.

Randomly picturing Heyman as Nia Jax's mouthpiece and Nia wearing Brock's 'ufc fighter shorts' over her regular gear while Paul Heyman says "My Client Nia Jax"

I think Corey Graves would be a great manager for Shinsuke.

I think he's fine the way he is. I also think WWE tells him to "Jap it up" because he seems to talk better anytime he's not cutting a promo on TV.

Heyman hasn't worked with anyone but Lesnar since...well, probably ever in WWE, if you think about it.

Ideally it would be great but it's pointless to put him with anyone full time given WWE's booking style. Heyman hyping someone on the mic does nothing when they're the same 50/50 booked guy they've always been. (See: Cesaro).

Heyman/Punk worked great together

Heyman and Punk were great.

Heyman would be a great mouthpiece for almost the whole roster but he's also not a good fit for most of them as well. Don't see it working with Nakamura unless several big changes were made to his character.

Heyman with Lesnar and Heyman with Punk were great because they felt like genuine pals and also meshed well with his managerial style. Both were lacking when it came to being paired with Axel, Ryback, and Cesaro.

I wanted to like both guys at the time, but when you really look at Punk's run, it wasn't that crash-hot. I loved his 2009 stint and the potential of the 2011 and onward one, but Punk/Heyman was kind of from that "bleh" period in time.

This is a big factor too. Heyman can obviously talk. But even when he is put with someone that isn't a doomed experiment, you can see how his language gets neutered.

Plus, that Cesaro thing was only a cup of coffee. That could have been glorious if they kept that as a pairing. Heyman could have worked so much better with Ryback without all that "... are they lovers?" subtext being shoehorned in. I still maintain that WWE themselves derailed Henning* when they decided to scrap his push three weeks in and just make him a meatshield mook that kept Heyman from getting his ass kicked. They had plenty of bodies on the roster for that role, they didn't have to sacrifice someone they were supposedly building up to the Job Gods. Hell, even working OPPOSITE of Samoa Joe, he was doing his damnedest to get Joe over as a credible threat to Brock's dominance... just to have him lose clean in the middle of the ring by being killed dead by a single F5 and then not be able to get back at Brock without other people being involved. If they were going to stick to their "let's cut down the number of finishers in a match" mandate, that was fine... but it is back to PPV matches being finish swaps and kickouts.

Ultimately, that's the big downfall here: Paul can be an asset to nearly anyone, so long as the brass doesn't go "BORED NOW!" and go focus on trying to get Roman over some more. I'd venture to say he could even make Mojo tolerable.

That said, and to answer the question, no.

Shinsuke doesn't need Heyman, and really, Paul would prob'ly question that pairing himself.