one of the things I love the most about airtable is the agile way in which i can create a table, add a field, create rows, then convert that column to a single-select to constrain future row input, then later convert the same column table links and have airtable convert all my single-select values into rows in a new table. its the un-schema workflow; what a wonderful way to work up a data model.
a nice related feature would be the ability to collapse multiple records in a table, merging the linkages of each record into a single record. it would help on the clean-up side of the agile modeling process i outlined above.