Folks,

How would I go about editing the L&NE template to take advantage of the fact that I've got the BLW L&NE set and therefore make those RS-2s the deployed choice instead of any other?

It's probably covered in the manual, but I've been very afraid to tamper with it or the template.

You can use either Activity Master or ConBuilder to substitute rolling stock into loose consists in the template activity file, and also into the player and AI consists.  By modifiying the template activity file, all activities generated with AG will include your stock.

It doesn't much matter if you mess up the base template, since all you would need to do is download and reload -- the base files will overwrite those which you modified.