Googled passed proxies are needed to scrape URLs using Google search, without jamming up your own IP with Google. So yes you do need them for scraping G, BUT with the new Scrapebox it's got 20+ new search engines in it that don't seem to care how often an IP makes search queries, and they will find the same URLs that G would.
I just started playing around with it and I can download a few thousand proxies without any testing at all and scrape thousands of URLs with the other search engines.
To answer your question, yes you can use scrapebox without google passed proxies for scraping URLs, just don't post with them because they suck for that.