With the family adventure genre, which is what this would fit under, there is more room to mix the structure/format up. Though for a trailer you really need to have expansive dynamics and this comes from not only building the dynamics in terms of expression for each instrument/section, but also from scoring fully for each section in regards to the harmony and pitches. When you reach the very last hit, you should really be reaching every single instruments max (127) velocity and expression/mod (whichever the VST responds to) as not only the volume increases but the timbre of the instruments changes, though I guess this depends what library you have as to how well it achieves this.
There isn’t enough variation in the orchestration either, remember that a trailer is usually split into three ‘Acts’ to display an outline of the film without giving much away so sticking to the same orchestration and/or harmony/motif for too long may not always work, sometimes it does though, but it still usually needs to build in some way, either dynamically and/or with orchestration/harmony. Whether it’s for a trailer or not, the orchestration is still very bare.
Whatever motivates you to write is great, and any practice is practice, though it may perhaps be more beneficial to try to write more like film score such as; Harry Potter, Hook etc or if you want to hear the best of the best in action writing trailer cues then Two Steps From Hells ‘Devil Wears Nada’ album is some of the best family adventure trailer cues that I’ve heard, particularly Clock Tower Parade.
This video (2 part) will help you more than anything I could type in regard to using the DAW/VST’s, since he explains using VST instruments very well and complete with some visual graphs too.
Part 1: Mike Verta's V.I. Techniques - Part 1 of 2 - YouTube
Part 2: Mike Verta's V.I. Techniques - Part 2 of 2 - YouTube