HTTP request-response efficiency

This code has been used for over 8 years on various projects at the software company I do work for.  The code calls a dll that consumes various xml requests for data access, other functionality and returns xml with data, status of request, etc.  

I am seeking help and guidance with the following questions:

1.  Should the oServerHTTP object be terminated after use?  If so, how  .close?  = nothing?
2.  Is there a more efficient object  than MSXML2 or different methodology to use to make the request and manage responses?
Open to non-Microsoft technologies (node.js,, etc)
3.  In terms of reducing strain on the server, what are the key factors that go into improving the use of this dll?
4.  Are there any viable hardware appliances or other hardware possibilities that should be considered to improve efficiency and throughput between http requests and the dll?



This question is posed in order to broaden my base knowledge in order to make better recommendations and decisions.  Please feel free to point me to particular buzz words, google searches, etc as part of the answer.

Here is the sample code that is used repeatedly:

Set oServerHTTP = Server.CreateObject("MSXML2.SERVERXMLHTTP")
oServerHTTP.open "POST", "http://localhost/myerp/isapi/erpwebrqb.dll", False
oServerHTTP.setOption(2) = 4096
oServerHTTP.send oSendDoc
   
If Not oServerHTTP.status = 200 Then
Else
End If
   
set nodes = oServerHTTP.responseXML    


Thanks