this is not really a Semantic MediaWiki specific question, thus I am
also forwarding this to the general MediaWiki list to broaden the
audience and attention for your question.
Personally I do not like auto translated content and rather have no
translation than an automated one. However having this if you push
massive amounts of pages and at the same time providing an approximate
idea about its contents is all about could indeed be a solution. A
matter of taste and objective.
So if you think 1 or 2 is ideal for you you will most probably have to
look for a new maintainer or ask the old one to fluff things. More or
less a matter of money and/or goodwill.
Suggestions 3 to 5 are basically the same. Just depending if you want to
install pre-bundled software or not. Here you need people to do the work.