Understanding 照相 and 照片
I would say that 照相 is a noun, and should be interpreted as the action to take a picture: 我們去照相 （We go to take pictures.）In this context, you can use 拍照 in lieu of 照相。And it can be separated as a verb and a noun: 我拍了几张照 or 我照了几张相。
To summarize:

照片 = (noun) photo
照相、拍照 = (noun) the action to take pictures
我照了几张相、我拍了几张照

照、拍 = (verb) to take a picture
相、照 = (noun) photo



Furthermore, when the context is clear enough (i.e. talking about taking pictures), you can use independently 照/拍 as a verb:

你照/拍了嗎？ = 你拍照/照相了嗎？

Beware that 照/拍 alone have different meanings, that's why the context should be clear enough to use them alone.