Nice! (for speed at least)
I would show your team some examples of external URLs pointing at the non trailing slash versions of your pages and explain the downside of the 302 redirect. Also consider that people and bots visiting those URLs will be adding overhead to your server, and on Amazon that will equal increased cost (small as it may be, the pennies add up!)
Reading the link you provided it looks like the default behaviour of the page metadata redirect under the s3 console is to create a 301 redirect. That makes me think the 302 is coming from somewhere else. Look at the following URL:
http://docs.aws.amazon.com/AmazonS3/latest/dev/HowDoIWebsiteConfiguration.html
It looks like you can add advanced redirects under "Enable website hosting -> edit redirection rules". I'd explore if there are redirects listed there and maybe chat to your developers further.
While you are it I spotted two other issues for you to consider. Currently the index.html files in your directories resolve to the same page as your main directory. I would 301 those pages back to the parent directory (slash version). Or you could add canonical URLs pointing back to the parent directory (with trailing slash). I'd make a case for adding canonical URLs to all pages.
Also, you currently have a number of redirect chains e.g.
http://www.strutta.com/resources/posts/share-your-contests-and-sweepstakes-all-over-social-media 301 redirects to http://www.strutta.com/resources which 302 redirects to http://www.strutta.com/resources/.
You need to find the original redirect and change it to 301 redirect to the trailing slash version of the directory. Screaming Frog can help you find these redirect chains.