I can't find the option to filter out things like DLCs and Soundtracks in the Shop browser. Could someone point me out to somekind of advanced filters? Or if there are none, could the Team add filter to show only Full Games, please?

the store ui is just ported in... scroll to the bottom and press the "show more"... that will give you the full [standard] store ui that web browsers get

no you can't see your changelog, keys or special dlc within Galaxy and YES it has been asked for again and again but [for now] you need to use a web browser to see those items after you pay for them at the store

Perhaps I am wrong but I believe you are misunderstanding the OP's request.

If I am not mistaken they wish to occlude "DLC", "Soundtracks" etc from their searches in the store when trying to search for games to purchase, and they wish to see ONLY full release titles in the store front.

I am unsure if this can be done however- someone more experienced may be able to assist.

i understand the question they asked and yes that is the basic gist of it... what I am saying is this has bugger all to do with Galaxy 2 because the store ui is its own system that just gets ported into a web browser or Galaxy

so to be clear, NO you can't filter out Dlc from a store search... reguardless of what system you use to look at the store