Insert/delete time and splitting in projects - how does it really work?

Trying not to screw up a project the first I do, I try to read up a bit in this(even doing backup first).
My reference is Cubase mostly here - which has numerous options when doing this - I come back to that.
 
So Insert/Delete Time is two operations - one split and one move.
Or am I missing something here already - are existing clips always kept in whole?
You are to perform manual split first?
 
It's clear for the most part what will happend, when it comes to audio.
But what about splitting - how is it done in regard to insert/delete measures?
I mean if you put now position in the middle somewhere, and on some tracks that may be in part of a clip so the must be some splitting going on.
 
And for midi there are notes that can be detected to overlap - what to do, keep on left clip and shorten duration, split in two different notes with different durations, or keep to right clip etc. In midi there are often tiny ticks here and there that will be cut or kept - even when doing single clip operations, but over a full project there are concerns.
 
There are a number of options what is to be selected after operation is done, looking at split operations separately in Sonar. But I'm more concerned about what happends to content - it does not say much.
 
What I try to do mostly is create new space over en entire project - for 8 bar break or whatever.
Cubase Arranger tracks has some options how it splits ranges on timeline - Make Real Event Copies, Don't Split Events - basically what I described above changing durations and stuff or keep notes on one side.
 
To do the same in Sonar it's Insert Time that will do this manually.
Sonar moves automation(events as I read it) with this operations, but that is pretty much what it says.
How are notes and controllers in midi clips treated?
Lengthy notes of a pad kept in run into this newly created space - or two notes/controllers created, one for each side?
 
Any tutorials and/or read up one can do on this?
Or if somebody did the trial/error method and knows?
 
Is it the same operation as Split on a single clip, so one can experiment with one clip and see what happends?
 
Thanks.