1. The search results page itself is not controlled by the plugin, so you can use the theme editor/widgets to place anything you want on the results archive – as long as the theme supports that.
2. Sure, you can change the redirection method. However I still recommend keeping it as is, it’s much better to have those arguments via the default GET method.
2. It’s to send information to the results page handler:
– asp_active -> tells if the query is originated from the plugin and should trigger an override
– p_asid -> unique search ID
– filters_initial & filters_changed -> tells that the form data is initial and form data had not been tempered with yet, so based on that more efficient queries can be constructed
– current_page_id -> used as reference to the originating page ID
Unfortunately there is no other way to send this information.