User-shared queries: Dynamic SQL vs. SQLCMD
Just to get these out of the way:


Technically speaking, both of these options are "dynamic" / ad hoc queries that are not parsed / validated until they are submitted. And both are susceptible to SQL Injection since they are not parameterized (though with the SQLCMD scripts, if you are passing in a variable from a CMD script then you do have an opportunity to replace ' with '', which may or may not work depending on where the variables are being used).
There are pros and cons to each approach:


SQL scripts in SSMS can be easily edited (which is great if that is a requirement) and working with results is easier than with output from SQLCMD. On the down-side, the user is in an IDE so it is easy to mess up the SQL, and the IDE makes it easy to make a great variety of change without knowing the SQL to do it.
Running scripts via SQLCMD.EXE does not allow the user to easily make changes (without editing the script in an editor and then saving it first). This is great if the users aren't supposed to be changing the scripts. This method also allows for logging each execution of it. On the down-side, if there is a need to routinely edit the scripts then it would be quite cumbersome. Or, if users need to scan through 100k rows of a result set and/or copy those results to Excel or something, then that is also difficult in this approach.





If your support folks aren't doing ad hoc queries and are just filling out those variables, then they don't need to be in SSMS where they can edit those scripts and make unwanted changes.

I would create CMD scripts to prompt the user for the desired variable values and then call SQLCMD.EXE with those values. The CMD script could even log the execution to a file, complete with time stamp and variable values submitted.

Create one CMD script per SQL script and place in a networked shared folder. A user double-clicks on the CMD script and it just works.

Here is an example that:


prompts the user for the server name (no error checking on that yet)
prompts the user for the database name


if left blank, it will list the databases on the specified server and prompted again
if the database name is invalid, the user will be prompted again

prompts the user for the OrderIDsSeparatedByCommas


if blank, prompts the user again

runs the SQL script, passing in the value of %OrderIDsSeparatedByCommas% as the SQLCMD variable $(OrderIDsSeparatedByCommas)
logs the execution date, time, ServerName, DatabaseName, and OrderIDsSeparatedByCommas to a log file named for the Windows Login running the script (this way, if the log directory is network and there are multiple people using this, there won't be any write contention on the log file like there might be if the USERNAME were to be logged in the file per entry)


if the log file directory does not exists, it will be created



Test SQL script (named: FixProblemX.sql):

SELECT  *
FROM    sys.objects
WHERE   [schema_id] IN ($(OrderIdsSeparatedByCommas));


CMD script (named: FixProblemX.cmd):

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION

SET ScriptLogPath=\\server\share\RunSqlCmdScripts\LogFiles

CLS

SET /P ScriptServerName=Please enter in a Server Name (leave blank to exit): 

IF "%ScriptServerName%" == "" GOTO :ThisIsTheEnd

REM echo %ScriptServerName%

:RequestDatabaseName
ECHO.
SET /P ScriptDatabaseName=Please enter in a Database Name (leave blank to list DBs on %ScriptServerName%): 

IF "%ScriptDatabaseName%" == "" GOTO :GetDatabaseNames

SQLCMD -b -E -W -h-1 -r0 -S %ScriptServerName% -Q "SET NOCOUNT ON; IF (NOT EXISTS(SELECT [name] FROM sys.databases WHERE [name] = N'%ScriptDatabaseName%')) RAISERROR('Invalid DB name!', 16, 1);" 2&gt; nul

IF !ERRORLEVEL! GTR 0 (
    ECHO.
    ECHO That Database Name is invalid. Please try again.

    SET ScriptDatabaseName=
    GOTO :RequestDatabaseName
)

:RequestOrderIDs
ECHO.
SET /P OrderIdsSeparatedByCommas=Please enter in the OrderIDs (separate multiple IDs with commas): 

IF "%OrderIdsSeparatedByCommas%" == "" (

    ECHO.
    ECHO Don't play me like that. You gots ta enter in at least ONE lousy OrderID, right??
    GOTO :RequestOrderIDs
)


REM Finally run SQLCMD!!
SQLCMD -E -W -S %ScriptServerName% -d %ScriptDatabaseName% -i FixProblemX.sql -v OrderIdsSeparatedByCommas=%OrderIdsSeparatedByCommas%

REM Log this execution
SET ScriptLogFile=%ScriptLogPath%\%~n0_%USERNAME%.log
REM echo %ScriptLogFile%

IF NOT EXIST %ScriptLogPath% MKDIR %ScriptLogPath%

ECHO %DATE% %TIME% ServerName=%ScriptServerName%    DatabaseName=[%ScriptDatabaseName%] OrderIdsSeparatedByCommas=%OrderIdsSeparatedByCommas%   &gt;&gt; %ScriptLogFile%

GOTO :ThisIsTheEnd

:GetDatabaseNames
ECHO.
SQLCMD -E -W -h-1 -S %ScriptServerName% -Q "SET NOCOUNT ON; SELECT [name] FROM sys.databases ORDER BY [name];"
ECHO.
GOTO :RequestDatabaseName

:ThisIsTheEnd
PAUSE


Be sure to edit the ScriptLogPath variable towards the top of the script.

Also, the SQL scripts (specified by the -i command-line switch for SQLCMD.EXE) might benefit from having a fully-qualified path, but not entirely sure.