The Joy Cons themselves do not have a headphone jack. Not sure it would be feasible for either the Joy Cons or the Grip...

What's Poke'mon, and Animal Crossing? - Analysts 

I wonder if they'll sell the "pro" version for $299 and do a price cut for the standard version, or they'll just sell the "pro" for more than $300. I hope the first option is what happens

It gets a bit tricky because then you'd have to sell the new smaller version for lower than $250, considering how pricing usually happens it would most likely be $200, and making new models takes a lot of development time. Even if they'd make a profit off that, it would probably mean a lot of the technology of the Switch would be lost. I've said before that they could cut out the dock and sell the Switch Lite for lower but was criticized for it . They did it with the New 3DS though. 

I could honestly see them just releasing a smaller model for $250 and a Pro model for $300 and just waiting to discontinue the regular model after it is sold out. 

I hope they go with 16nm X2, ditching denver cores.
It outperforms X1 by 50%. It could be used for performance or less energy consumption.

Means that a switch mini could have a lower wattage compared to regular switch HH mode. So, more battery life.
Also, joycons are expensive, it has it own board, communication components, and are 2 of each. Building everything in a single board, and not needing extra communication components could help a lot in decreasing the price. If it runs only in the HH configuration, with a limited maximum clock, it would help in the design, not needing extra cooling, could help also.
Just the charger and the mini switch could have been sold by like 170$.
Add a mini dock that allows to stream to tv, with space to charge joycon(not included), 200$. So you could have the regular switch experience (changing the game modes) by just buying an extra joycon pair.

The pro version, x2 , same size to fit the dock and joycons, less bezels, 1080 screen, more storage. In HH mode you could choose 2 configuration:1- to save battery (hence will run in the same mode as the mini, allowing more battery life), or 2- performance mode, for a regular switch dock experience on HH.
While in dock, more clock it allowed. So dynamic resolution games would benefit.

A Switch Pro with all the bells and whistles would be awesome, but all I ask for is a better Wifi chip, I mean my 2DS gets a farther connection range for goodness sakes...

I'd buy a Switch Mini

I wouldn't be surprised if the branding is something like Switch 2 and Switch 2 Plus.

That would be a terrible mistake.

I'd prefer something like Switch Go! and Super Switch.

Switch Go! sounds great, but Super Switch, not so much. Switch Plus would be more appropriate imo.

Or, if they increase the storage space to 64GiB, Switch 64 (Switch-ty Four?)

*Enter N64 Kid meme here*