I suggest running away as fast as possible... 

1) No, we have thankfully not had any experience with more than a few hundred databases...

I'm guessing that the problem is with your use of the BETWEEN operator.  It's difficult to get correct results using BETWEEN with temporal values that contain times.  For example, if...

Does this mean you're going to post an example where the outer join is faster than NOT EXISTS?

Each unique user (or machine) that ever accesses the database directly or indirectly requires a CAL.  I.e., it's not concurrent licensing, it's Microsoft licensing. 

DBCC SHOWCONTIG('Tablename') WITH TABLERESULTS.

Look at the MaximumRecordSize value.

You can use sp_helpfile to get the file size.  It's also displayed in Enterprise Manager (EM).  You can use EM to see both the size and the amount used by...

Using COUNT() outside of a query will return 1, no matter what the argument (unless you try NULL), so neither of the local variables you test will ever equate to...

I agree with Frank.  If a query can be written using NOT EXISTS rather than an outer join, that's usually the way to go for best performance.  Even if the...

SELECT Id, CreateDate, CaseTitle

FROM [Case] c

WHERE NOT EXISTS

(SELECT *

 FROM [Action]

 WHERE Id = c.Id)

AND CreateDate >= '20030101' AND CreateDate < '20040101'

Yes; that's what I meant by "more useful." 

http://www.sqlservercentral.com/columnists/awarren/worstpracticedefiningrowsthatexceedthemaxlength.asp

As for your original question, you could use the Object Browser in QA to script...

Wouldn't something like this be more useful?

SELECT SUM(Length)

FROM syscolumns

WHERE OBJECT_NAME(Id) = 'Tablename'

You can replace the apostrophe with two apostrophes in the front end, but the better solution is to use a parameterized command object. 

Does the table have a clustered index?

The difference between using DML and using TRUNCATE is that your update statement is fully logged.  If only some of the values are non-zero, you could try something like this:

UPDATE Table1 SET...

For job notifications, why not just use XPSMTP?

http://www.sqldev.net/xp/xpsmtp.htm