Your answer is wrong. Surprisingly enough OP is actually correct with their assumptions...
Intelligence affects computer based crimes, 9 and 18 nerve.
It's the reason why you can succeed hacking on something like a 30 nerve bar, having just 10k intel can make up for the rest.
The effects are very minor for the mostpart for other crimes but in the case of computer crimes it is noticeable.
Speed has an effect on crimes too, most notably with the shoplifting crimes, having higher speed will improve your success on them... although the effect of this is extremely minimal as it's a low tier crime, most crimes have a success rate cap too, and these lower tier ones are reached very easily with just minor amounts of crime experience.
Endurance used to raise gym gains too... but not sure it does anymore in the newer gym system...
This information did all used to be listed in the old manual (
http://www.torn.com/manual.php) but sadly this was deleted with RESPO and the information was lost to new players.