Using web2py for a user frontend crud
This double/redundant way of talking to my DB strikes me as odd and web2py does not support python3.

Any abstraction you want to use to communicate with your database (whether it be the web2py DAL, the Django ORM, SQLAlchemy, etc.) will have to have some knowledge of the database schema in order to construct queries.
Even if you programmatically generated all the SQL statements yourself without use of an ORM/DAL, your code would still have to have some knowledge of the database structure (i.e., somewhere you have to specify names of tables and fields, etc.).
For existing databases, we aim to automate this process via introspection of the database schema, which is the purpose of the extract_mysql_models.py script. If that script isn't working, you should report an issue on Github and/or open a thread on the web2py Google Group.
Also, note that when creating a new database, web2py helps you avoid redundant specification of the schema by handling migrations (including table creation) for you -- so you specify the schema only in web2py, and the DAL will automatically create the tables in the database (of course, this is optional).
I was asked to port a Access database to MySQL and
provide a simple web frontend for the users. 
The DB consists of 8-10 tables and stores data about
clients consulting (client, consultant,topic, hours, ...).
I need to provide a webinterface for our consultants to use,
where they insert all this information during a session into a predefined mask/form.
My initial thought was to port the Access-DB to MySQL, which I have done
and then use the web2py framework to build a user interface with login,
inserting data, browse/scroll through the cases and pulling reports.
web2py with usermanagment and a few samples views & controllers and 
MySQL-DB is running. I added the DB to the DAL in web2py,
but now I noticed, that with web2py it is mandatory to define every table
again in web2py for it being able to communicate with the SQL-Server.
While struggeling to succesfully run the extract_mysql_models.py script
to export the structure of the already existing SQL DB for use in web2py
concerns about web2py are accumulating.
This double/redundant way of talking to my DB strikes me as odd and
web2py does not support python3.
Is web2py the correct way to fulfill my task or is there better way?
Thank you very much for listening/helping out.