HQ
Canoness w/ Powerweapon, Brazier of Holy Fire, Book of St. Lucius and Jump Pack
Power weapons are scary at S3
Give her Cloak of St. Aspira, Book, Jump Pack, and then BP/MC-Eviscerator or IP/Blessed Weapon
Canoness w/ Powerweapon, Bolt Pistol, Book of St. Lucius and Litanies of Faith
7 Celestians w/ Heavy flamer, Sacred Standard; Veteran w/ Powerweapon and Boltpistol
Elites
6 Celestians w/ Heavy Bolter
Never been a real fan of Celestians, and I've never tried footslogging Canoness' either. So I can't give you any advice here.
Troops
10 Battle Sisters w/ Heavy flamer and flamer; Veteran w/ Auspex
10 Battle Sisters w/ Heavy flamer and Meltagun; Veteran w/ Auspex
10 Battle Sisters w/ Heavy flamer and Meltagun; Veteran w/ Auspex
10 Battle Sisters w/ 2 Meltagun; Veteran w/ Auspex
I play Mech, so I don't really know footsloggers, but I can tell you this: footslogging squads are best off at 12-14 sister/squad instead of the minimum 10.
Fast Attack
7 Seraphims w/ 2 Hand Flamers; Veteran w/ Eviscerator and Bolt Pistol
5 Seraphims w/ 2 Infernopistol
Get rid of the second squad to up your regular BS count. It will be horribly shot up before they can reach a tank most of the times anyway, unless you spend a whole bag of faith points on them, or you play with a LOT of cover. The first squad is nice, but could use another member for the optimal 8.
8 Dominions w/ 4 Flamers; Veteran w/ Brazier of Holy Fire
Rhino w/ Extra Armour and Smoke Launcher
I'm not against Dominions with Flamers really, I'm not against Dominions at all (heck, I have a squad of them with Storm Bolters in my regular list - even though they are rather bad). It's just that in a footslogging list, where you have only a single Rhino as the only transport on the board, this little tank will be so horribly shot up the minute you try and get into Flamer range, that it's not worth it generally. Unless you turn around and go all-mech, get rid of this unit entirely, and get more Sisters.
Heavy Support
8 Retributors w/ 4 Heavy Bolters; Veteran w/ Auspex
7 Retributors w/ 4 Heavy Bolters; Veteran Auspex
Exorcist w/ Holy Icon
Get rid of the Auspexes. Since the minimum infiltration distance is 18" in LOS, you'll have to roll
really good on those 4D6 to make it worth the points. If you got rid of all the Auspexes, you could get another Sister, to go in the second squad.
The Exorcist needs Extra Armour and maybe Dozer Blades. Get rid of the Icon.
In short, your list lacks mobility. This isn't the end of the world though, since footslogging Sisters are built for resiliance, and not speed. To obtain resiliance, you must have larger squads than you have now though.
Purg