Working backwards:
Knockbacks were recently added to the game. The higher your strength, the better your chance to knockback an enemy. You can increase your chances even more by wielding a battle axe, war hammer, or two-handed sword. There is no concrete information on strength vs knockback chance.
For strength vs. damage bonus, I can point you to the only source I know of:
http://userpages.monmouth.com/~colonel/rvm.html - The Rogue's Vade-Mecum. What you're looking for is about two-thirds of the way down that very long page, and you'll want to use the V4 listing, as the way strength vs damage bonus is calculated didn't change much for V5, which is what Rogue Touch is based on (for example, there's only one strength level 18 - version 4 of Rogue mirrored the way Dungeons and Dragons did it). There's one caveat here: CD didn't use all of the stats from version 5 of Rogue straight up, so the numbers may be slightly different, and again, there's no concrete chart.
As for strength having a to-hit bonus, I'm not sure. I had originally posted here:
viewtopic.php?f=2&t=410#p2717 that high strength did provide a to-hit bonus of some kind, but then backtracked and
requested that CD chime in on the issue to get a definite answer. That request went unnoticed... hopefully this one will not (I made that one a pretty bright red color too).