I must admit I’m disappointed with the video export functionality as well. This was a big reason for me upgrading from Cubase to Nuendo, and as it stands it’s not really useable for me.
Just little things … our business supplies H264 video with AAC striped at 320 kbps as a standard preview, and I can’t select that audio quality. I also can’t quickly restripe the video that’s in there (like how Logic Pro does it), so it needs to be re-rendered every time. That takes awhile, and also doesn’t even seem to offer the full benefits of re-rendering: I tried exporting two videos on the video track as one and it wouldn’t include the second video in the render. I was excited/hoping for similar options to the Audio Export window, where I could bounce out multiple videos (for example, different TVC edit durations) at the same time using cycle markers. Plus, it’s just really buggy and fails for me on offline export.
I think Studio One’s video export, introduced in 4.5, is (while not perfect) a good example of doing this right. I really hope this is improved quickly.