I think that it would be pretty difficult to develop these ideas in my opinion. The entrance of each instrument was pretty effective. This is in E major, right? It is a tough key for Flutes, Oboes, Clarinets, and Bassoons. Also, it is alright to have a short 30 sec intro, but then (especially if you are writing a classical symphony) you must state the theme. Preferably very loudly.
The orchestration was ok. During the middle of the clip, from :21 to :30, the violins were not very clearly heard and their melody wasn't well defined. It looks like you crossed lines between the two, which blocks out the counterpoint. To change this, either increase the octave between them or change the melody.
This could work... but mabye as a second mov.
