Understanding .docx XML tags for better performance

Hi,

I am using MS Word API to generate .docx which contains the data fetched from DB, in which i am applying the respective styles, fonts, symbols, etc. If the data fetched from the DB is quite huge, then there is a problem in displaying those data in the .docx file. I found that internally MS Word 2007 will write some content through tags which may not be needed to display the data. Hence i am figuring out what are the necessary MS Word tags needed when converting into a .xml file. So that i can avoid unnecessary tags and build only the respective tags which are needed to display the data. Hence i am planning to write my own .xml with the MS Word tags which are needed, than generating a .XML from .docx file

My queries are:-

1) Whether it is right that the MS Word will generate some tags which may not be needed during the conversion of .docx to document.xml? That makes it heavy? If so what are the tags , so that i can avoid them when write by own .xml file.
2) Please send links to understand about the MS Word tags and its advantages, which tags are needed and which are not ?
3) Whether my approach to write a new .xml similar to document.xml (.docx conversion) is worthy one to go forward so that i can build the .xml with the tags i needed , so that i can improve the performance of the data display?

Please shed some light into it and thanks in advance..

Thanks,
Rithu