There's 3 ways of botting (& profiting)
- either make one sick account, high level, quested etc and bot bosses (zulrah) or wyverns / double nats (high level, high profit)
- manually make bot army and use the best scripts and tools you can (& hope to not get banned)
- make easy suicide bots and dump gold every 24 hours (my favourite, especially when you can bot the entire account, including tutorial and quests)
edit: as far as IP goes, many "pro" farmers will say that proxies/ip flags are a myth and that they always bot on one ip, but some of them have a rule of thumb; 10 accounts per ip to avoid 'chain bans' or so they say