Timeout in seconds here allows you to have any SQL command sent to either source or target database fail after N seconds. You may want to set this number to 0 (which means never time out and wait for as long as needed) if your server is slow and may take a lot of time to respond.
Column nullability allows you to change the NULL/NOT NULL for all tables at once.
Copy default values can be unchecked if you don't need them.
Incrementing columns can be unchecked if you prefer us not to flag columns as incrementing (identity, auto_increment, serial - depending on the database).