Just putting up coving, got some questions please

1.  Instead of spending ages having to mix up coving adhesive and spreading it onto the back of the coving with a trowel which takes ages
Q1. Can you get something suitable, in a tube, that’s ready to apply, as per silicon sealants ???

2.  Having applied some finishing plaster to hide the joins between each section of coving (both straight bits and in the corners) the newly applied plaster is cracking
Q2. Why is this, and what can I do about it ???

3.  When it comes to the small gap (between coving & ceiling and coving & wall) apart from mixing up more finishing plaster and taking hours to push a small amount into these gaps all the way around  
Q3. What do the pro’s do ???   I can’t believe they would spend a day or more doing this 8)

Thanks
Dusty

Either the ready mixed adhesive or you buy it powdered that you mix yourself.
As AM says put plenty on and wipe off any excess with a wet sponge same in the joints and corners.
You may need to support the coving with some nails while the adhesive sets.
Shouldn't give you too much trouble.

Ken