Alright, so I've been on a shiny hunt myself in this MMO for the last two years and this is everything I've learned:
• The time until you get a shiny will obviously vary, but my save is currently at 1,300 hours with ONLY the Hoenn campaign done. I spend a couple of hours each day going through boxes upon boxes of Pokémon and I always have donator status active. So be prepared for the long haul. In terms of efficiency, I don't think there's any way to be more efficient than hatching 5 at a time with a Flame Body or Magma Armor Pokémon in the lead.
• Do not use bracers, and do not use anything other than regular Pokéballs. If / When you get your shiny, you can sort out those IVs and the Pokéball of choice. How I earn the money is by catching the male breeders myself, and selling all of the 31 IV Pokémon I caught on the GTL. This usually earns me enough money to pay for the Dittos on the GTL when I need them. Other than that, yes I have spent a lot of money on reward points for extra fast hatches ( $400 according to my payment history ) but if you can avoid the temptation I would try and refrain from doing that.
• The answer to your last question is one of my favorite things implemented in this MMO. In PokéMMO if you breed a shiny Pokémon with another shiny Pokémon, the offspring will also be shiny. This is when you'll want to use your bracers and Pokéball of choice. If you reach this stage, what you'll be doing is buying shiny Pokémon of the same egg group as your Feebas ( if female ) or a shiny ditto ( if male ) and using the bracers to turn your Feebas into a 5x31 IV Pokémon. This will be expensive, but nowhere near as tedious as finding your shiny in the first place.
Hopefully this helps you in some capacity! Now if you'll excuse me, it's been 4 minutes and the eggs have most likely hatched.