Does muse have prebuilt templates you can simply load pix into?
No. The idea of Muse is to be free to actually design websites. If you are able to find an old copy if Apple's iWeb, this would be more suited, or try Jimdo for ready-made templates.
The great thing about Muse is that the ready made templates available on the web are so easy to edit, take a look at http://www.museonatheme.info they only have a small selection but the templates are the cheapest I've seen.