The fish system isn't ended.
It's only work the process of fish with baits, and the function of its.( burning, double battle..)
But, for make it work before you need to put the routines that makes this effects.
Finally, the offsets you put in the last message is:
086B143A -> the pokemon in the first slot of "fishing wildbattle" (in each map is diferent, is the wild pokemon data table)
08084f3c -> ldr r0,[rx,rx] (or something like this) is the part of default routine that loads the table of the first pointer and choose one pokemon randomly for make a wildattle.
08084f36 -> i need to delete 8 bytes, to make my hook.
Put ldr r0,.your_routine_to_select_the_pokemon_via_fish
Bx r0
Buh, i have a coffee machine as a pc, so skype makes my pc slow.