NCH Debut Screen recording gives me good video for playback in VLC but importing into Vegas Pro 19 lacks all fine detail. (Short video IS about 3.5MB) Can someone give me some guidance here please? Should I be using some other screen recording software?
You should post your recorded File Properties when asking for guidance. I don't think anyone here knows what NCH produces or what options are available.
To answer your second question, many people here get good results with OBS.
Here are proven settings for OBS that have worked well in Vegas Pro.
https://www.vegascreativesoftware.info/us/forum/faq-what-obs-studio-settings-work-well-with-vegas-pro--109925/
This is embarrassing... My cause for concern was the poor quality in the Vegas preview. Everything looked just fine once I actually rendered it (FYI using either NCH Debut or Vegas's own screen capture)
@Alan-Cohen What quality was your Preview on?
Preview was on "Auto." - amazing how much difference "Full" makes.
If it was on Preview Auto, see how much difference Best Full would make.