1. When i change the name of an object, maybe a sprite, it auto changes it's name in the event and action system, but only if directly affected.
But i access a value of a class in a phrase, it doesn't, but the formula keeps working anyway.
When you rename an object, it should update the name everywhere, even in expressions (I think you use the term "phrases" to mean "expressions"). If it doesn't, it's a bug! If you found a place where the name is not updated, please report a bug, it needs to be fixed.
. If i want to send a capx file with features of standard edition to a user with demo of c2 only, can he open, export and safe the project without restrictions?
If the project is within the free edition's limits (100 events, 4 layers per layout), it can be opened, edited and exported in the free edition as well. If your project exceeds the free edition limits, then the free edition can still open it and preview it, but not add or edit any events or export it. Basically, if you have under 100 events and only 4 layers on each layout, it should work 100% in the free edition as well.
. How can i access the heigth/width of a layer in the event system?
All layers have the same size as the layout.
. Is there a way to rotate a textfield? If not, will that be implemented soon?
Not yet - is it an essential feature? I didn't think many people needed to rotate text.
. I need too access multiple Sprites with one object name, so that i dont have to write every event for new with the same methodes. Is there a way to do so?
It sounds like you need the Families system from Classic. It allows you to refer to multiple sprites via one object (e.g. "Monster", "Ghost" and "Troll" all as just "Enemies"). It's on the todo list, hopefully it won't be too long. For now I'm afraid you'll have to get by with copy-paste.