The utamo vita will protect a total of 40% (dont know the actual formula of how this is calculated) and 28% of your level in total on my own experience is something close to a third of your mana if im not wrong.(even though is a separated bar from your mana it will still consume your mana)
The cooldown is 14 seconds and last 60 seconds but the mana shield bar can be refilled by a mana shield potion that cost 1 silver token
They also added a new spell that cancels the mana shield and it is "exana vita"
The impact of your level has been raised by more than 16%, and the impact of your magic level by 40%
The impact of your level has been raised by an additional 14%
Sources:
Personal experience in the test server
https://www.test.tibia.com/forum/?action=thread&postid=31554#post31554
https://www.test.tibia.com/forum/?action=thread&postid=29478#post29478
https://www.test.tibia.com/forum/?action=thread&postid=26575#post26575
If there is still a doubt about it make a comment and gladly i will try my best to answer it and update this answer :D