Bagel and gluten development question

Bagels are supposed to be dense and chewy.  You want the dough to be strong, so I wouldn't worry about pulling a windowpane.

For me personally, I find bagels are the easiest of all breads to make.  The formula I use involves mixing at first speed for three minutes, then at second speed for six minutes.  That's it.  Bulk ferment for an hour, shape (I use the log method), then into the refrigerator overnight.  The slow overnight fermentation will give you a nice, chewy crumb.