As in your own language, i think it's important to make simple sentences to be understood (and sometimes to understand oneself)

I've always thought that people who use complicated sentences and words, generally, don't understand their own arguments...

Because when you can't simply explain something, that's because you don't know it very well.

I would never simplify this down to short = good, long = bad, or even to simple = good, complex = bad. It's a case of 'know your audience', and in this case, Esperanto is like every other language.

Certainly I will speak in easier, shorter sentences when I'm talking to a beginner (a beginning Esperanto speaker, or someone who doesn't speak English well). But in a conversation between me and another fluent speaker, there's no reason for me to simplify my speech. I speak, in that case, in Esperanto or in English, with sentences that may be long or short, simple or complex. In Esperanto, my word order will also be more varied than it would be if I were talking to a beginner. The vocabulary I use will be more complex when talking to a fluent speaker than when talking to a beginner.

Esperanto is able to express everything that other languages do, and it would be a shame to speak only a simplified version all the time. When speaking with those who are capable of understanding Esperanto's full range of expression, there's no reason not to use these traits.

That is an exceptionally good point, yes I think particularly in a forum where many people will read the statement written that it is best to be clear, simple and concise, but when speaking to someone with equal comprehension skills it is good, and wonderful to be able to use the language to its fullest extent...I so can't wait until I can lol...fingers crossed.