There is no braille cave to get deoxys.
Currently there are no Braille caves you can interact with to change Deoxys' form. To get an Attack Form Deoxys you need to trade one from Pokemon FireRed. This is due to Deoxys' default form being different between the GBA Pokemon games. This mechanic was likely put in to encourage trading between the games. In every game since Pokemon Emerald there has been a way, usually a meteorite, that will let you change the form of your Deoxys.
no
By using cut.
you will NEVER find deoxys in shoal cave the ONLY WAY is to get the aurora ticket from an event or action replay
dotted hole is on the south side of six island. (the sapphire is in there) a little extra info: dotted hole does have braille in it.
its 20
The braille cave is south-west of Paciflidog, use HM dive when you see a dark patch of water surrounded by six rocks.
You have to Run around the Cave 3 times
On island one, there is a cave with a ruby and a full set of braille alphabet.
kyogre-cave of oregan regice, regi steel, regirock (doing all the braille puzzles) rayquazza-sky pillar. deoxys and jirachi-space centre after 50 launches (50 weeks)
google braille and translate the braille in the game on a piece of paper, or look up Regice on Bulbapedia for direct translations.
Meteor cave