I have a Nook Touch and I have to admit that other than for highlighting I do not use the touch feature too much.
At times I found it confusing for the device as it won't know if my touch was made with the intent to highlight a word at the right side of the page or with the intention to go to the next page.
For Pocket Edge where I have touch screen and stylus I prefer to work with the stylus when I am reading PDFs (landscape mode though). It is a lot more precise and easy. That is in study mode reading
When in leisure mode reading I prefer not to use the stylus but the touch function.
As M92 is for studying I think that it is actually better to just handle everything with stylus and buttons.