For the very end of your todo-list: Did you think about a database connection to fill e.g. the comboboxes?
don't know how to implement this with raw lite-c, because i don't want to create a such complex script.
It can be used freely in our project?
yes, but it would be nice to note my name in the credits (
MasterQ32 or
Felix Queißner(Queissner is also accepted ))