In answer to your questions:
Where is the livery editor?
It would be nice, but not vital. If that's literally the only thing that matters for you in a game then there is this game called 'Need for Speed' which has been knocking about for a while.
Where is the event creator?
In the online lobby, last time I checked.
Where are the leader boards?
Some have been introduced on licence tests, and there were online leaderboards on Prologue. Not to far fetched to imagine they're on the way.
Where are the non "stage based" tuning options?
There are plently of tuning options, that's one part of the game that there is very little need to fiddle with.
Where is the improved AI?
Although improved, it could definitely still go further. Whether the AI is good or not, there is hardly ever any satisfaction in beating anything other than a real human, which is why so many people choose to race online.
Where are the sound improvements?
Some have come, others on the way. Cheers for bothering to read my post so carefully.
Where is damage?
Like others have said, improved. However, I recommend just not crashing into things then this is no longer an issue.
Why is that so hard for you to believe?