thanks for the reply!
1. Yup I knew he was supposed to be there but the cave is empty as you can see here:
https://gyazo.com/32817de2086b220385d50d6ee1d6eaa2 and to prove I haven't caught/fought him already here's my pokedex:
https://gyazo.com/e50443fb0adda51ad46fd32aed5e5d0a
2. I defeated Gold but the guy is still in the Cerulean cave. As you can see the champion isn't in MT Silver anymore since I defeated him:
https://gyazo.com/b35e4047e37cead2f374524f43375194 (could this bug happen because I defeated Gold and not Red? Maybe you coded it so the guy leaves when Red is defeated but not Gold?)
3. I saw a screenshot of a player (maybe you) getting a GS Ball after talking to Chansey so I managed to find the pokemon center and tried it but it doesn't work. I defeated the league twice could that be an issue?
https://gyazo.com/a6f1a7ac10d45c6e90e57d9a4dd3f3ac and yes I checked my inventory
(Also I agree that GS-Ball should only be given after you defeat the Champion :D)
4. Oh okay thanks, that's a cool system :)
I use Visual Boy Advance on my PC
PS: I have never used cheats nor any exploits to skip stuff, I played everything normally