A good idea, if you're up for the challenge, is to use learning theories from AI.
For example, create a program the records click durations, mouse paths, and pretty much any information you can think of. Then, play the game for a good amount of time (collect data over several playing sessions). Now you can create a statistical normal distribution for certain parameters like click time, how often you check things like inventory, stats, etc.
You can use the Box-Muller transform to generate normally-distributed random numbers using AHK's Random function as a base. You fit these random numbers to the parameter distributions that you measured in your recorded gameplay to create a realistic distribution for the parameter based on your actual gameplay.
Why go to these lengths? Because you can make your bot, statistically, exactly the same as you.
It is well known that the IRS has techniques to detect fraud simply by examining the distribution of digits in your tax returns. The same principle could be applied by RS to seek out botters. Even when we randomize our clicks, they are not good enough. A perfectly-uniform random distribution is not realistic. If RS devs get smart enough, they will start measuring these kinds of advanced statistics (though it doesn't seem that they do this yet).
In my experience, as the previous poster said, mouse path is not a factor. Keep in mind that it COULD be in the future, so there's no harm in developing a good mouse path randomizer. Read up on cubic splines! They're a relatively painless way to make a nice path. If you're really smart, you can add perlin noise to the cubic spline path to get a path that's absolutely, fantastically human-like. These are just some advanced concepts if you want to take your bot to the next level
If you want to get really insane, run bots on two computers and develop a simple chat AI to allow the bots to have random conversations between accounts. This will certainly seem human-like if you can make the conversations real enough (I think mine are! My bots pick topics like life, girlfriends, school, etc. and have a huge database of potential topics and permutations of the things they can say. It's very convincing

)
Hell, if you want to be even more insane, you could allow the chat AI to interact with real players. That's something I plan on doing eventually but have not been able to achieve yet (I mean...chat AI...that's a whole different field! But still...imagine!)
Oh yeah, and have your bot do things like check stats, look at friend lists, and maybe even change the music, every now and then.
So why should you consider all those crazy things? Well, I've been botting for around 4 years. Banned once in the early days before I did really good randomization. Reprogrammed everything with more elaborate methods (like those detailed above), never been banned since. That's 1 ban, total. That's why you should consider those things
Plus, designing a really good bot for your own personal use is just plain fun.