Hello, Chproto!
What has already been said by Barry and Jirka, I endorse those comments. Barry's idea of breaking the project into smaller projects, much easier to handle! Jirka's suggestion of producing(rendering) the video might straighten out the audio/video mismatch. but what has me puzzled is, assuming you're shooting with a modern digital videocamera that produces AVCHD or MP4 video files, which, by their nature, are high definition, why would you want to touch them up with Video Denoise? By their own nature, AVCHD and MP4 videos are "pristine", clear, sharp and well-defined! They need no touching up at all! If the image is dark, you might want to brighten it a bit, but you use the brightness setting in Fix/Enhane for that purpose.
Video Denoise comes into its own when capturing old VHS, Beta, Video-8 or Hi-8 cameera tape content. When captured the image quality might appear a bit grainy, Video Denoise cleans up that graininess beautifully, add a bit of tweaking of the contrast and brightness, plus, if you've a mind to do it, convert the 4:3 aspect ratio to 16:9 using CLPV and you can, jokingly, lie to your friends by saying you shot the clips digitally! Ha-ha. They'll never know the difference or the truth, but you will. It'll be your little secret! But for content already shot digitally, Video Denoise is not necessary!
Cheers!
Neil.