Your comments

You're absolutely right. We'll soon add this feature.
You're right. We'll soon change the behaviour of the scrollbar. Thank you for suggesting this improvement.
What do you mean by "database documentation"? The ERD diagram is a documentation of sorts. If you want a document describing all tables and columns, there is no such feature in Vertabelo. You can download the Vertabelo XML file and transform it into documentation with a simple script or program.
The default is your database default, probably SIGNED. We don't have plans to change the UI with respect to signed/unsigned types.
Support for ENUM and SET is on the way. It should be available in the coming weeks.
You're right. This feature is on our roadmap. We'll add it in the coming weeks.
The import of .dmd files is not possible yet. We're planning to add import from various database modeling tools in the future but certainly not in the next couple of months. For now, you can try our reverse engineering tool or import from SQL scripts.
Just type INTEGER UNSIGNED in the Type field. Only the most common types are shown in the Type selection layer. You can type whatever you want in the Type field, Vertabelo will verify if the type is correct.
It is not supported yet. We have added it to the roadmap for the nearest months. The feature should be available by the end of October.

Thanks for the suggestion. I have given you 10 bonus points for this feature request.