With more people using mobile phones, smart phones and tabs, definitely most of them will like having video in emails. It is a good thing that there are products like Brainboxvideo that can help you with videos in email. Let me add that it also has features such as keyword research, marketing research, press release, video creation. You bet. It's beyond just any video distribution tool.
The emails are written to address a variety of questions- If you have a video which is relevant and adds credence to what you are saying - by all means add the video. If however if detracts the ubjcet from the key focus, then please avoid it rather do not add it.
Having video in emails can potentially give you higher conversion rates. Why? With video in email, there's a higher degree of capturing your audience/reader's attention.
Suggest its better to provide a link rather than the actual video. Makes it easier and faster to load and less likely to trip over firewalls etc.
It could be better to upload it on youtube first and paste the link in email.
yes
if it further proves your point in an argument yes.
No