HI kkx,
I cannot answer all of your questions, but perhaps some of them:
We are talking Tamron Adaptall-2 lenses and PK/A custom mounts for these lenses.
Aperture Range: It will (should) show 2.8 - 22 irrespecftive of whether you use TC or not in AE-mode. The TC only reports the seeting of the lens; it is not "intelligent" and will not compute the actual f-ratio. But you will get (should get) proper exposure anyway.
F--- and need to jiggle: Yes, we all know about that. It is a fact that these adapters are delicate items and some are more worn than others. But
The fact that you report that your lens will not stop down when the lens is in non-AE mode indicates something more problematic. In non-AE mode, you can only operate with the camera body in M-mode, but then the lens should certainly also stop down when you release the shutter. Are you sure you have set your program dial at that M-mode?
Also, the question about the "black tap" indicates to me that you are not completely familiar with the procedures for using and installing the mount. You MUST depress the "black tap" to shift from AE to manual. If you use force here, you may damage both adapter and lens. I suggest that you download the instruction manuals (pdf-files) for both adapter and TC from my homepage here:
PhotoDocs
You will find the adapter manual in the second and the TC manual in the third block of documents. Please also note the instructions for mounting and dismounting the adapter - IN PARTICULAR that the aperture must be set at its widest!!!
Overexposure: I don't know your 72B, but I have 8 other adaptall-2 lenses and yes, some of them tend to over expose. It is quite easy to correct for that using the EV compensation. My lenses usually like a compensation of either 0 or some -0.7 to -1 EV.
Finally, if you haven't found your way already, I suggest that you vist the Adaptall Lens Club page in this Forum, where you will find a lot of valuable information and inspiration to the facinating world of Tamrom Adaptall lenses.
https://www.pentaxforums.com/forums/lens-clubs/59769-adaptall-mount-club-tamron.html
I hope, this helps a little bit.