Let's see here.....
For the final write-up you should include the basics: who did, how you know this, ect. Also why the evidence rules out the other suspects. If there is more than one perpetrator make sure you explain how you know this. So, yeah, basically I agree with dudeincolorado. I tend to subscribe to the more-detailed/more-information/more-facts-is-better theory for this. Not long rambling, but concise with as much support as you can.
For flame tests, my team used nichrome wire and it worked well. There really is no way to avoid sugars caramelizing, you just have to work around it. Cobalt glass can be helpful, but it is up to you. You can really work it either way.
I never used a conductivity tester, we had one in our box but we never used it. You could. It is definitely an option. I recommend a dichotomous key of powders. It works well (especially since you are allowed notes). Just figure out what tests are quickest and will help identify the powders.
Indiana University 2012
-- Bio and Spanish Majors
University of Chicago
-- PhD track Molecular Biosciences: Human Genetics