In my personal belief, the prioritization should be:
Heroes > Equipment > Faith > Limit Breaking
1st Priority (Heroes) - I believe that having a varied pool of heroes will help you in any aspect of the game. There are certain heroes best used in arena, events, raids, etc. so having a decent variety of heroes is definitely my priority. Get that 3 Star Hero/Summoner Selector if you believe you lack in support/firepower specially you mentioned you still dont have one archer. It doesn't matter yet even if they have bad faiths in the early game.
2nd Priority (Equipment) - The next thing heroes need are those equipment as they rocket their stats up. Get those 5 star equipment selectors specially if you already have 2/4 or 3/4 of a set and have a smile once you get those bonus stats in completing them! It doesn't matter yet if these equipment sets have bad suffixes (e.g. Champs sets with Wizardry, etc.)
3rd Priority (Faith) - Now that you have decent pool of heroes with decent equipment sets, it's time to fix the Gods in which your heroes worship. Get those pixie selectors and Have your Mages finally worship Athena instead of the mighty Hera! I usually try to reroll their faith with 5 star fodders before deciding to buy a pixie as they are cheaper!
4th Priority (Equipment 2.0) - After correcting your Heroes' faith, it is now time to correct your equipment sets' suffixes. You dont want your assassins/ninjas wielding complete 5 star set equipment with all wizardry! Go reforge them with 1 valianite. It might be costly but who knows when will Lady Luck strike?
5th Priority (Limit Breaking) - Ok, I get it, your Faye HD has good faith (Kratos/Hercules) and decent equipment sets (5 Star Sets with "Of Defense") so what now? The next challenge is to get them to their maximum potential at level 40! Go back to those 3 star hero/summoner selectors and brag those Level 40 Avatars!
6th Priority (Costume) - No explanation needed. Those little stats and unique aesthetics do not really add any in-game value for now (Personal opinion).
Good Job!!! Well explained.
Thought point 4 and 5 can be concurrent running, since LB use gold only. The other priority u need to think of is the aura direction. It may not that critical, but it does affect ur formation when u want to link up all the 5 heroes.