I would like to be able to select multiple nzbs from the search result and then download them all at once so that I do not have to select each individual nzb from the search result to start downloading.

The way this could work would be to introduce a checkbox next to each item in the search result. When you have finished selecting the items you want (by selecting the checkboxes), you press a "download selected" button (or similar). This would send all selected items to the queue and downloading starts.

Especially useful when downloading lots of tv episodes.