DTA suggesting inadvisable ammendments

Hi all

I have actioned the recommendations on a trace file put through the DTA.  It has however made our system even worse performance-wise!

It suggested to remove certain indexes which we rely on heavily to increase search speed and performance - yet after the amendments were actioned, the system was reduced to a crawl.

A copy of the trace file SQL used to produce the results is attcahed is at the bottom of the post.

My questions are:

1. would anything in the trace attached have made the DTA get rid of the indexes?
2. have I missed anything in the trace event definition to make the DTA remove the indexes?
3. are there any pitfalls or issues with running recommendations from the DTA that i'm not aware of?
4. What are the advantages of using the trace/profiler combination instead of using the missing index/performance DMVs?

Thanks in advance.

-- Create a Queue
declare @rc int
declare @TraceID int
declare @maxfilesize bigint
set @maxfilesize = 30

-- Please replace the text InsertFileNameHere, with an appropriate
-- filename prefixed by a path, e.g., c:\MyFolder\MyTrace. The .trc extension
-- will be appended to the filename automatically. If you are writing from
-- remote server to local drive, please use UNC path and make sure server has
-- write access to your network share

exec @rc = sp_trace_create @TraceID output, 2, N'G:\Trace\Trace', @maxfilesize, NULL 
if (@rc != 0) goto error


-- Set the events
declare @on bit
set @on = 1
--Show XMLPLans
--exec sp_trace_setevent @TraceID, 122, 34, @on
--exec sp_trace_setevent @TraceID, 122, 1, @on
--exec sp_trace_setevent @TraceID, 122, 7, @on
--exec sp_trace_setevent @TraceID, 122, 8, @on
--exec sp_trace_setevent @TraceID, 122, 64, @on
--exec sp_trace_setevent @TraceID, 122, 14, @on
--exec sp_trace_setevent @TraceID, 122, 26, @on
--exec sp_trace_setevent @TraceID, 122, 11, @on
--exec sp_trace_setevent @TraceID, 122, 12, @on
--exec sp_trace_setevent @TraceID, 122, 5, @on

--RPC:Completed
exec sp_trace_setevent @TraceID, 10, 34, @on
exec sp_trace_setevent @TraceID, 10, 1, @on
exec sp_trace_setevent @TraceID, 10, 7, @on
exec sp_trace_setevent @TraceID, 10, 31, @on
exec sp_trace_setevent @TraceID, 10, 8, @on
exec sp_trace_setevent @TraceID, 10, 16, @on
exec sp_trace_setevent @TraceID, 10, 64, @on
exec sp_trace_setevent @TraceID, 10, 17, @on
exec sp_trace_setevent @TraceID, 10, 18, @on
exec sp_trace_setevent @TraceID, 10, 26, @on
exec sp_trace_setevent @TraceID, 10, 11, @on
exec sp_trace_setevent @TraceID, 10, 12, @on
exec sp_trace_setevent @TraceID, 10, 13, @on
exec sp_trace_setevent @TraceID, 10, 6, @on
exec sp_trace_setevent @TraceID, 10, 14, @on

--SP:Completed
exec sp_trace_setevent @TraceID, 43, 34, @on
exec sp_trace_setevent @TraceID, 43, 1, @on
exec sp_trace_setevent @TraceID, 43, 7, @on
exec sp_trace_setevent @TraceID, 43, 8, @on
exec sp_trace_setevent @TraceID, 43, 64, @on
exec sp_trace_setevent @TraceID, 43, 26, @on
exec sp_trace_setevent @TraceID, 43, 11, @on
exec sp_trace_setevent @TraceID, 43, 12, @on
exec sp_trace_setevent @TraceID, 43, 5, @on
exec sp_trace_setevent @TraceID, 43, 13, @on
exec sp_trace_setevent @TraceID, 43, 6, @on
exec sp_trace_setevent @TraceID, 43, 14, @on
exec sp_trace_setevent @TraceID, 43, 62, @on

--SP:StmtCompleted
exec sp_trace_setevent @TraceID, 45, 1, @on
exec sp_trace_setevent @TraceID, 45, 7, @on
exec sp_trace_setevent @TraceID, 45, 34, @on
exec sp_trace_setevent @TraceID, 45, 55, @on
exec sp_trace_setevent @TraceID, 45, 8, @on
exec sp_trace_setevent @TraceID, 45, 16, @on
exec sp_trace_setevent @TraceID, 45, 64, @on
exec sp_trace_setevent @TraceID, 45, 17, @on
exec sp_trace_setevent @TraceID, 45, 18, @on
exec sp_trace_setevent @TraceID, 45, 26, @on
exec sp_trace_setevent @TraceID, 45, 11, @on
exec sp_trace_setevent @TraceID, 45, 12, @on
exec sp_trace_setevent @TraceID, 45, 5, @on
exec sp_trace_setevent @TraceID, 45, 13, @on
exec sp_trace_setevent @TraceID, 45, 6, @on
exec sp_trace_setevent @TraceID, 45, 14, @on
exec sp_trace_setevent @TraceID, 45, 62, @on

--SQL:BatchCompleted
exec sp_trace_setevent @TraceID, 12, 34, @on
exec sp_trace_setevent @TraceID, 12, 1, @on
exec sp_trace_setevent @TraceID, 12, 7, @on
exec sp_trace_setevent @TraceID, 12, 31, @on
exec sp_trace_setevent @TraceID, 12, 8, @on
exec sp_trace_setevent @TraceID, 12, 16, @on
exec sp_trace_setevent @TraceID, 12, 64, @on
exec sp_trace_setevent @TraceID, 12, 17, @on
exec sp_trace_setevent @TraceID, 12, 6, @on
exec sp_trace_setevent @TraceID, 12, 14, @on
exec sp_trace_setevent @TraceID, 12, 18, @on
exec sp_trace_setevent @TraceID, 12, 26, @on
exec sp_trace_setevent @TraceID, 12, 11, @on
exec sp_trace_setevent @TraceID, 12, 12, @on
exec sp_trace_setevent @TraceID, 12, 13, @on

--SQL:StmtCompleted
exec sp_trace_setevent @TraceID, 41, 34, @on
exec sp_trace_setevent @TraceID, 41, 1, @on
exec sp_trace_setevent @TraceID, 41, 7, @on
exec sp_trace_setevent @TraceID, 41, 8, @on
exec sp_trace_setevent @TraceID, 41, 16, @on
exec sp_trace_setevent @TraceID, 41, 28, @on
exec sp_trace_setevent @TraceID, 41, 64, @on
exec sp_trace_setevent @TraceID, 41, 17, @on
exec sp_trace_setevent @TraceID, 41, 18, @on
exec sp_trace_setevent @TraceID, 41, 11, @on
exec sp_trace_setevent @TraceID, 41, 12, @on
exec sp_trace_setevent @TraceID, 41, 5, @on
exec sp_trace_setevent @TraceID, 41, 13, @on
exec sp_trace_setevent @TraceID, 41, 6, @on
exec sp_trace_setevent @TraceID, 41, 14, @on


-- Set the Filters
declare @intfilter int
declare @bigintfilter bigint

set @intfilter = 50
exec sp_trace_setfilter @TraceID, 12, 0, 4, @intfilter

set @bigintfilter = 2000000
exec sp_trace_setfilter @TraceID, 13, 0, 4, @bigintfilter

exec sp_trace_setfilter @TraceID, 35, 0, 6, N'CAAP'
-- Set the trace status to start
exec sp_trace_setstatus @TraceID, 1

-- display trace id for future references
select TraceID=@TraceID
goto finish

error: 
select ErrorCode=@rc

finish: 
go