You almost had it
First off, datarate is in "C:\Program Files\EverQuest\datarate.txt"
so just go there to change that.
Second, to do the patchme thing, create a shortcut to eqgame.exe. On its properties thing instead of
"C:\Program Files\EverQuest\eqgame.exe patchme"
do
"C:\Program Files\EverQuest\eqgame.exe" patchme
Good Luck!