yeah its called "if you dont know what your doing get a pro to do it
"
as for this hole in the gearbox where is it located?? if its only into the clutch area (get a plate for it, dosn't take much to tap 4 holes and stick a piece of steel over it to stop stones etc getting into it.) it might have nothing to do with the raunching of the gears etc.
first thing i would do is bleed the clutch system and go from there as celica_tommo said, look for leaks also THEN start looking at the more $$ things.