Is there a tool out there that will go through a schema, compare the current values, and return a report of what columns are near the capacity of their data type? I am looking for a tool that can give me insight into limitations that may be reached soon. An example would be forewarning that I am at 60% of reaching the limit of an INT on a column).
I don't know of a tool to purchase, but you could create a SQL job that could analyze things for you. I'd hoped that the Redgate software would do it, but that's pretty much for comparing schema of databases between servers (I suppose you could use it to find all the INT columns in all tables, but you can look that up yourself in system tables)
Have the script look at each Column you're concerned about and check its value against the max value. Use conditional statements that only send an alert when the value is relatively high.