I'm so glad you have questions.
● Yes, the range of the jutsu is short, which means that the clone can't be further away form you, or it will vanish. I don't see a problem why you couldn't take advantage of some else's smoke to make your own technique, it's absolutely valid.
● The clone is tangible to some limits. The clone should take a 1-2 light punches/kickes, but a strong punch/kick can easily destroy it. A sharp thing (kunai, shuriken, blade), has no problem against it either.
● Now, I don't really get this question.
● Referes to the upper answer; a strong kick/punch, sharp thing or a few light kicks/pounches.
● The speed of the smoke depends on the factor of wind. If wind blows at your chest, it will aggravate the spreading of the smoke. Both usual natural wind, and the Wind that has been made and controled by chakra. We see another weakness of the technique here. But for this technique, it's not very important how fast the smoke will spread out, because you can create the clone in front of you and don't use a lot of smoke, but just as much too need to make the clone.
● You can't use the techniques that come from your mouth, that's why the wrist launcher is the best sollution. But, we need to practice doing it with the gas mask too, because you never know when you'll need the skill.
● The clone can use only smoke related techniques.
Anything else? Plus, I think we've pretty much named the advantages and disadvantages. Now, you just put things together.