hmmmmm...
well, for the master seeing as you have the 'suffer not the unclean' vow, i'd go for a simple power toy as you'll be wounding on 3's or so usually! and this way you'll also get the extra attack too!
if you want your dread getting into the thick of it quickly, consider giving him a drop pod!
the sword brethren really need some numbers in order to maintain their assault abilities... (keep in mind that -1I penalty!) and also, try to keep the unit an even number for scoring unit purposes.
also, drop hunter-killer MISSile on the rhino! i've yet to actually see one of those things hit its target?!
the problem with deep striking assault termies is they have to weather a turn of enemy fire... unless you put them in the crusader, i'd swap them for some regular termies.
and again, only having 5 isn't great for an assault unit either!
those 6-man squads aren't going to be as effective when they mix short & long ranged weapons...
as you really need some anti-tank, i'd say go for either lascannons or rocket launchers.
the big squad needs to lose 1 model for scoring purposes too!
personally, i just don't think you have enough numbers and you're very light on the anti-tank front...
some melta bombs on your marshal & chappy are recomended, as is changing at least one of those 6-man squads' heavy bolter for a lascannon/rocket launcher.
i honestly drop the termies altogether, and get some more men... (maybe a 16-18 man crusader squad?!)
hope this helps,
cheers!