First, I'd like to say a big thank you for a great software! It's far superior to most out there! I use almost all features for my hobby making homemade videos and have worked with video editing both as a hobby and also in my professional life.
That said, I wanted to suggest a few things that I feel would get your software a bit closer to perfection, so here they are:
1) The timeline and working on clips can be time consuming and I find that it would be so helpful if there was an extra button next to "previous frame/next frame" called e.g. "go back 5 secs" or "go forward 5 secs" (or 3