Nice guesses at the cross, but a 'Tatzenkreuz' in black isn't a knight templar cross since those crusades in the mediterranean ran with
red on white, whilst the crusade in the east ran this black on white.
The Templars are a fine addition to the marine-codices,as 'crusades' wasn't done then.
Their heraldry and names are borrowed from a order not so widely known, , maybe to make it less obvious where
GW found something to
use in their own products.
As one of the few here who got called a
BT... yes I like them.
They got a complete and well written codex, where only a single unit needed a
FAQ.
They got a nice conversion kit.
Invented the crusader
LR.
You get scouts as meatshields...
Survived a survivor thread at dakka:
http://www.dakkadakka.com/dakkaforum/posts/list/450/269775.page#1229605
..and painting them isn't so difficult.