Templars want to be in combat, equipping your main squads with bolt pistols and chainswords maximises their combat abilities, easy enough. I do usually run a couple of min sized Crusader squads with las/plas and bolters, but their job is simply to sit on objectives and annoy enemy vehicles.
As Raktra says, a few Neophytes in a large footslogging squad are basically free movement generators. Pop a plasma gun would on one, watch is face melt and potentially gain that squad another 6" move. Hell, stick a Chaplain with a few Cenobytes in there as well and you've got decent odds of getting a free 9" move for the price of a single Neophyte.