Okay. I am a scripter, so let's clear some things up. No, they can't detect clients. They can detect if your character, while botting, appears to be seeing through objects they shouldn't be and clicking on them. This would mean it was reflection or injection. A good bot using these methods won't be caught.
Second. Jagex makes a color map of the movements your character makes ( or so we think ). So if a pattern is repeated the color of the map will get darker in that area. If you click in the same place every time, at the same rate, the color will be extremely dark and send out flags. Again, a good bot won't have these problems, but an auto clicker certainly will.
Third. All the money I have made from sythe has been from one bot I wrote months ago. Botting is at the point where jagex can't catch it if you invest in a good script. They are starting to play the game more realistically than humans in some cases. If you are getting banned, use a good script and make sure it has realistic human movement.
Fourth. DON'T DO THE SAME THING OVER AND OVER. Even if you have a good bot, if you always log in the same, and do the same kind of things on different accounts, jagex will group this play style together and ban you for botting. For example, if you are botting sharks...start some at the fishing guild, some at catherby, have some fish swordfish. Have different wait times for every account.
Blah I am sure this is a mess. Botting is honestly a lot better than it was in the past and it is almost at the point where jagex won't be able to catch it.