The Templars separated themselves from the chantry so they definitely dont have access to blue lyrium from the official channels ie. dwarves. They must have been truly desperate to start using red lyrium as a source.
No not all of the Templars are using it, and we really don't know why the red templars are using and ingesting it, where they got it from or why they're attacking people besides the fact it makes people crazy.
See we don't truly know who is in control of the lyrium trade. Considering the templars policed it and transported it and everything, it is entirely possible the Templars either continue to control part of it, know where to get lyrium through the black market, or just took the majority of the chantry's lyrium with them when they left.
I don't see Lambert leaving the order in desperate need of lyrium.
I agree with you, we don't know what they did with the lyrium in the chantry or if they found another supplier, etc.
I also don't think Lambert is desperate of finding or needing lyrium aswell or even considers using the red Lyrium and considering what happened to Meredith I don't see him and his Templars using it.
Perhaps the Red Templars are a sub-faction of the Templars. I can't imagine all of the Templars left the Chantry.
Correct they are indeed a splinter faction of the Templars and bioware already confirmed this during pax and again via game informer in their coverage.
There seems to be 3 factions of them now the ones loyal to the divine, the ones loyal to Lambert and the red Templars.
Below is an excerpt from one of the articles that state that the red templars are splinter faction.
A splinter faction known as the Red Templars, who are essentially Templars who have taken to using Red Lyrium, is threatening the town for unknown reasons.
http://www.gameinfor...tion-intel.aspx