where should a ftp mine gold (needs to be by bank,must be more than 2 ore rocks)

Crafting guild.

 

 

 

You can use the cabbage ring to get close to fally and the cabbage ring to get close to the guild. Well it saves some time atleast.

Crafting guild or karamja by the lesser demons

Crafting Guild (7 rocks), Karamja Dungeon (4 rocks) or the Crandor Northeast Shore (3 Rocks) are probably the best f2p places for gold.

Crafting Guild is actually one of the worst place to mine gold now, since most people tend to go there for gold too (heavy competition in most worlds)

 

 

 

On the other hand, I find the karamja volcano mine tend to be full of gold most of the time, followed by Scorpion pit and Edgeville dungeon (long trips, but guaranteed to have gold ore each time you mine a rock)