It would be better for you to find this yourself by creating a load on your Dev  server.
With out the included columns the plan may even ignore the new...

You need to either use Cursor

or try something like

@sql nvarchar(max)=''

 set @sql= 

It  might be difficult to suggest an approach by an outsider who do not know any thing about the database and the application it supports.
But even then the basic...

AWE is required only if you have 32 bit OS. 
SQL server buffer cache can use memory that you have configured in Max Memory

You can use the total...

I use the following query to monitor my tables

Select SCHEMA_NAME(t.schema_id) SchemaName,t.name,s.rows,p.reserved_page_count*8.0/1024 SizeMB from
sys.partitions S join sys.tables t on s.object_id=t.object_id and
s.index_id in...

certainly they are duplicate. The clustered index can benefit the same queries as the non clustered one. But  there is a chance that someone might have created it intentionally for...

Clustered index is the table, so you might want to recreate the index without the column, or you will end up with a heap table.
Since it is a Unique...

Try

SELECT CONVERT