Using 50% Critical hit = High Crit moves + Super Luck + Scope Lens. Then.... 100% Critical hit = High Crit moves + Super Luck + Scope Lens + BPed Lansat Berry, Focus Energy, or Acupressure? I've looked around and havn't found anything regarding adchieving 100% critical hit ratios
I'm not sure since it been ages...but I think your really just upping the damage in the critical hits. In pokemon stadium 2 on the n64, it had a trainer school which explained about the critical hit execution...and I think you'd get 150% damage with the stuff you listed, get super effective=MASSIVE OVERKILL But I don't think you can achive 100% critical hit rate, but you can up the damage so you can get near super effective (or higher) damage ratios...try that game and prehaps you'd better understand what i mean.
No you can't get 100% crits. and lansat berry and focus energy don't add up. Example if I used up the lansat berry and then tried focus energy it will say that Focus energy failed, and the same would apply to Acupressure, but using these is possible nightslash+ Super luck+scope lens OR Razor Claw+ lansat berry OR focus energy would be pretty good, but no 100% crits would be possible. However I do recommend trying to pile up attack boosts so you can cut like butter, and once you get a crit with attack stats piled ontop it will do a massive amount of damage.