Not with a soul- Spike avoided violence unless it was to help Buffy- at least to begin with. It was only when she needed him to be 'more' than he stepped up and became more like his big, bad old self.
So I still think, with a soul and without anyone around, he would've been more like Angel- hiding, eating rats, maybe fighting other demons but maybe not. Spike had the two guiding lights that Angel never had- Angel himself and Buffy. With Angel he knew that he wasn't alone in that situation and Buffy gave him support and purpose.