thanks for all the valuable feedback. In general we prefer bug reports or general KNIME questions via the KNIME forum. So you have already found the right place
You can attache log files to your forum posts or also provide example workflow as described in the Bug Reporting Best Practices. However when working with databases you should make sure that they do not contain any sensitive information e.g. connection strings etc. That is why it is better if you only past the part of the log file which contains the error including the stacktrace. If you want to or need to submit sensitive information you can do so via personal messages in the forum. Also it would be great if you could create a separate forum post with good titles for each separate problem. This way it is easier for us to keep track of them and for other users to find existing entries.
Regarding your problems
Can you give me some more information about the DB Connection Table Writer node problems, e.g. which database you are connecting to and which driver you are using. The log file with the SQL statement would be also very helpful. To enable JDBC logging in KNIME open the node dialog of the DB connector node and go to the Advanced tab. In the tab select the JDBC logger option as shown below.
Regarding your connection problem, we didn’t support this in general since it might cause problems for example when working with session base objects e.g. temporary table that will no longer exist if the connection was recreated. Then executing all nodes after the node that creates the session based object will fail and might trigger other questions. However I see your point which might be pretty painful especially if you have a very large workflow with lots of nodes to executed. I will open up a feature request and we will rethink the implementation. Maybe we will automatically create a new connection and output a warning the in the KNIME log that a new connection was created.
I will also open up a feature request for the DB Table Selector node and maybe other nodes that have the same problem. The restriction was introduced with the Input Type Mapping tab which gets its information from the input connection. However we might be able to just leave it empty and still allow the user to open up the node to at least specify the schema and table name manually.