It would be very useful to be able to set a maximum character length in a Text/Number column. A minimum would be good too. Attempts to enter answers outside the character limit(s) would be rejected like entering a non-date into a date field, with a pop-up message & admin override allowed.
The settings would be optional, so the current no-limits setup could remain the default for all new columns. Any min/max character length settings on the column would also translate to character length validation in any form using that column as a field.