First I'd suggest looking into "Change Tracking".  That would accurately identity any/all rows that have been modified since a certain date, and it wouldn't limit you to 4 days, you...

You also need to verify that the log is in status to be shrunk, like so:

SELECT log_reuse_wait_desc, *
FROM sys.databases
WHERE name = '<your_db_name>'

If the...

It would be more efficient to UPDATE existing rows and only add new rows, but if the number of rows is not too large just deleting and adding probably wouldn't...

I believe the I_S views are ANSI/ISO standard.  MS themselves were pushing them at one time. But they are too out of sync with the actual system catalog, i.e., too...

I never use the I_S views.  I've found them to be very slow and to cause blocking at times.  I know their official view definitions don't show why that would...

In cases where you do need a scalar function, for max efficiency, get rid of any local variables that are not absolutely required:

CREATE FUNCTION [dbo].[ufn_GetPlannersName](@intFeasibilityRequestId...

The table definition could be adjusted for efficiency.

At a minimum, get rid of the formatting chars in the phone# and make both it and zip char rather than...

As noted, the code should be retained for debugging uses, but it should be modified some.

1) Be sure to add this statement before it:
SET @DropTempDB = ''

I'll give it a guess.  Typically now you use OUTER APPLY to do the type of lookup  you're trying to do.  You also definitely don't need to join the table...

Add a clustering index to pre-sort at least a few of the values.  Just based off the very limited data you gave, I'd suggest something like this:

CREATE CLUSTERED...