-Mr. White will appear once you get the number of kills needed. Time passed or pretty much anyhing else doesn't matter, so you can get him pretty early if you know what you are doing.
-Illness ending depends on two factors. Job ending and money you have. If you get the scientist ending or assassin ending and you get the rich variant, then you will survive the illness.
-Hit chance can never reach 100%, but reaching 99% is possible. If the stats you had are correct, then you had about 97% chance to hit that bandit. You just got unlucky. The most important stat for hit chance is weapon skill. Basicaly 6 DEX will raise your hit chance the same amount as 1 weapon skill point.
-Ichor has multiple spawn points and it takes about three weeks for it to respawn. Only one can exist at a time and it never despawns.
I'm glad you like the game. Not everyone played it long enough to get that far.
Also, how did you get those stats so high? Did you just play that long or did you find some kind of exploit?