Vegasaur Quick proerties can do almost this in 2 steps.
First extend the events by 2 seconds, then apply. Then apply the fade-in.
Look at pictures attached.
What you need to do is to drag these events 2 seconds earlier after that, because Vegasaur keeps them in place.
If your events are just still pictures (jpg, png, etc), then you don't have to mess with "Take Offset".
Are you the author of Vegasaur?
Yes, it would be nice to have the ability to add fade in/out so that it extends the event.
So fade in before the current start of event, fade out after the current end of the event.
I remember I had some other ideas before, but forgot them.
I'll contact you when they come back :)))