Posted by rebecca3142
Is it true that you can bake multiple items at once and they will still all cook evenly? Ex. multiple sheets of cookies

Convection will tend to even out the heat in your oven but some do a better job than others. A convection oven with third element(also called European or true convection) may do a better job but it all depends on how the oven is engineered.

What about if they are two different foods, but can be cooked at similar temperatures? Is it true that the flavors won't combine?

No. There are some ovens with catalytic converters that do that.