Cleo decided to let me do some tests with attribute +100 rings and I found the following:
Int does not affect spell fumble, my sf remained at 5.9 all the time.
Dex affects AC and WC of ranged/melee attacks but only affects ranged dps, not melee dps.
I'm not sure whether all this is a bug but I thought it is better to report it anyway.
Now going to check the apt fix.

edit:
Apt seems fixed, I couldn't get it to not work.

edit 2:
The bank script is buggy.
I have some copper, some silver and some gold in my inv. When i want to deposit only the silver and copper the bank takes the gold instead of the silver/copper, the same happens when I want to deposit only silver or only copper.
Note: That bug only occurs when I have some gold/silver/copper in a pouch, doesn't matter if applied or not.