I put it a bit simple now (in a hurry :) )
Situation now: (correct me if 'm wrong)
Movable -> can move all around planner
Sizable -> can change start and end time
FixedResource -> can not move to other resource
Would like to have control over:
Change resource of item
Change starttime of item
Change endtime of item
hi,
You can further finetune the control of starttime/endtime and resource with the following events:
OnBeforeMoveItem
OnBeforeSizeItem
Yes, i see now :) did not notice the canmove/cansize parameters before 
but still would be nicer is it immidiate visible for the user through the UI , so the mousepointer won;t change when hovering over an item start/stop time.
but for now, we can do it with thi, thanks!