Hi SAMP people, I've got the solution for all of your problems:
-apply strict rules, admins must be strict as hell, no lenient or easy-going admins, only strict admins who totally know how to use their banhammer.
-stricter SAPD, yes, a stricter SAPD: everyone breaking even a small regulation must receive a warning, bypass 3 warnings and he gets kicked.
-Surveillance, admins must be present at all times and spectate/or use another nickname to hide from possible rulebreakers.
I swear if these pieces of advice are followed cautiously you will even solve your deepest problems. I heard that cheating and rulebreaking in SAMP is far worse than in VCMP and nobody complaining about VCMP so it would make sense.
To sum it up ban all of those motherfu**ing rulebreakers, I can tell about 100 players are banned from VCMP's argonath RPG server, eventually making the server a funner place and don't be afraid about your playercount, it will raise if cheaters get banned,
Peace.