In order to do those things you would need to go in at the Java level; MATLAB does not offer that level of control.
The most common way to handle mixed formats in a single column is to convert the column to string while it is in the uitable(), and converting the strings to appropriate numeric form if needed for computation.
A potential work around to prevent editing some rows would be to use a CellSelectionCallback, and if you detected that a logically read-only row was selected then to change the selection (even if it requires making the active object something else.) You cannot write into something you effectively cannot select.
