The note cut short at the end can be solved as follows:
1. Before you export, zoom out so that you see the entire composition in the PRV.
2. Drag the mouse cursor across the top of the ruler (where the beat and bar numbers are)
The grey area you draw will be the area that gets exported. Make sure the end is generously long.
This does not solve the problem of the reverb starting so late. I have tested with a piano sound in X1 and Sonitus:fx Reverb. I cannot reproduce the problem.
Could it be your sound starts slowly and for this reason the reverb is just not noticable yet?