IMO using butter and candy-ing the pecans is a bit unnecessary. Toasting the pecans is a good idea to bring out flavor and drive off some of the oils.
Here is a BYO article about nuts
I'm working on some sort of nut brew for the relative near future. A pecan pie beer does seem like a good idea. Im thinking toast the pecans, and use molasses or dark belgian candy sugar to give that rich deep caramelized sugar flavor.
Thanks for the motivation.