I don't want to lose link juice!
Absolutely! And wasting content is even worse.
I would do #5.
5. Assess the content to determine it's value. Value to me includes....
-- are there links pointing to this content?
-- is there traffic arriving through these pages?
-- are visitors who arrive at my site through other pages consuming this content?
-- the quality of the content
After I assess the items above I will take different routes depending upon the findings.
A. If content does not have links, does not pull traffic and is not being consumed I will probably delete the content and redirect the page to index.html
B. If content has links, traffic and consumption then I will decide if it merely needs a few edits. If that can be done I will keep the page. And, if that can be done I will look to add improved images, special interest boxes, "Did you know?" boxes, links to other relevant pages on my website. KICK IT UP A NOTCH!
C. If content has links, traffic and consumption, AND THE SAME TITLE IS STILL A GREAT CHOICE... but the article is really outdated then I will rewrite from scratch and post on the same page, always trying to kick content, images and message up a huge notch on this successful page. Then I will promote this major rewrite on my homepage, in feature boxes around the site, in my RSS feed.
D. If content has links traffic and consumption, and the old title is no longer a good choice, then I will rewrite from scratch, publish on a new page and create a boldface roadblock link to it in the first few paragraphs of the old article... and do the full onsite promotion. Eventually when traffic to old page starts dying then I will redirect. I want to keep the traffic from that old title flowing in because some noobs, old farts and out-of-date people will still be searching for those out-of-date terms. Conversion rate on these people can be good because they are looking for help or a book or someone (like you) to be their guru. Also, with this choice you now have TWO pages pulling traffic for different search queries.
You see, there is no generic answer to this question. You must assess on a case-by-case basis. Be careful not to abandon the noobs, old farts and out-of-date people. They can be valuable traffic.