First save your project.
Then submit a small portion of the project - say five minutes or so.
To do that easily, place the mouse pointer on the sequence scrubber (the red line) until it becomes a two-headed arrow.
Hold down the left mouse button and drag left or right to select (highlight) the region/s that you want to delete.
Right-click in the highlighted area and Delete Selected Region.
What remains is a small segment that you can upload and share, following instructions in the above link. Someone will check out the BluRay issue.
Did you try burning a conventional DVD? Using R/W or BE (read/write media) for testing will save you from making DVD coasters.