I'm desperate to quit doing that ooRP trade run.

[blubba]

You have to do whats right for you. If you like doing the diamond/niobium run, then you lead a sheltered life...
Do it when you need to do a job in Kusari and happen to be in Rhineland but don't stick to it. Trading is generally boring (sorry to all you people who think otherwise). The most excitement you get is from a well RP'ed pirate. Spice it up and make a point of visiting as many stations as you can along a route. You'll get all the commodity prices of those stations. Then try the return journey using a different path, again stopping at every station. Some earlier posts here give you some ideas for trade routes. Take them on-board and try them stopping en-route. You may find something in high demand, that you didn't know about elsewhere but happen to already know the very station where you can get it uber cheap.
Once you've done pretty much all the obvious runs, move to the edge worlds. Things can get pretty hot out there so don't expect to get away with much, pay the taxes and stop at every station/planet. This kind of 'Discovering' (did you like what I did there?) will enable you to develop your own character. Not someone elses pre-conceptions of what you should be. If you've done all the trading your stomach can handle, you might want to look at the seedier side of trading. The Smuggler.
You would now be equipped with all the best prices of almost every commodity and all the JH's and back roads into every system across Sirius. Use that knowledge. The law enforcers are more plentiful, generally better orgainised and far more unpleasant than the pirates. They not only tax/fine you, they destroy your cargo as well!
You now are armed with the 'knowhow' to make their life catching you as difficult as possible.
Fighting (or running) has to be more fun as a smuggler than just plain trading. I'd let you know for sure if I ever do it....

And lastly, above all else, have fun.

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