GIMP :: How To Disable All The Saved YAPs

I am working with literally hundreds of images. All of them either are now or will be jpgs. All I need to do is open them up, resize them and then:

1. Cut the canvas size down only on the Y axis and center the image

or

2. Increase the canvas size up on the Y axis and not center the image which requires then sizing the resulting single layer to image size

After that, I need to save it as a different file name and close it. That's it. No other functions, no other options, no other possibilities exist. This is the ONLY way that this job can be done, these images must end up in this format and size.

Again I am doing this to hundreds of files. I am being slowed down a LOT by all the foolish YAPs about "JPG can't handle this blank layer do you want to export, blah blah blah" and of course "You're saving as a jpg so what quality do you want to use?"

Speed is my concern. I don't care about the options because I don't have options for this project. I just want to get it done. All this clicking the chain to break the link between X and Y and then mousing to the Resize button and then hitting Enter twice but only if I sized the canvas up and using the layer options to resize it if I sized it down if extremely time consuming. I want to use the keyboard as much as humanly possible...all this mousing is creating carpal tunnel and the tabbing to buttons is stupid due to the 5000 tab stops on each popup.

Some of this I can accept...I suppose. But is there any way to disable the popups for the JPG warnings when I save? Again I am not wanting to discuss why I should be saving in XCF or the disadvantages of using JPG or anything else. I just want to disable the popups that are slowing this project down significantly.