http://doc.scrapy.org/en/latest/contributing.html#coding-style mentions 80 columns, but it doesn't mention multiple imports in a single line. So it is better to either fix imports or fix docs.

Never heard about alphabetical sorting of imports in PEP8. It makes sense when sorting imports with subpackages (subpackages will become grouped), but I don't think we should enforce or target it. Another way to sort is by module name length, but again, there is nothing in PEP8 about this, and while one may prefer writing code in such way, there is no need to enforce it.