Fire of the Faith theme Qs

[PDF]

Hi,
I've just started a game with Marignon "FoF" theme, which I've never tried before : so I'm not quite sure whether the theme's effect is what I expect !
From the doc, FoF gives "auto level 1 preaching" in each owned province, with "increased" (ditto - eg doubled ?) effect on enemy dominion.
What I understand from that is that a FoF-owned province is easier to convert than normally (whenever you get a province with enemy dominion) , and inversely it's harder for another dominion to convert them. So it looks pretty adapted to immortal pretenders, with a smaller risk to have a dominion "swap" during a turn.
It also helps on "dominion kills" (enemy eliminated when it has no dominion anymore), at which Marignon is naturally good even with base theme.
Apart from that I don't see anything else special - did I miss stg ?
Lastly it looks like the theme is a good deal : you get these special dominion effect for a cheapo 10 points (cost is 50 but minus heat 1 "gain" !). Apart from that you have exactly the same units, mages etc...
Again, am I right in that assumption ?

Thanks