Hey Arun,
Thanks for posting! I was beginning to think that I was the only Inbound guy anywhere that had to deal with this kind of issue
Yup, I created the same bug with redirect loops trying to get around the slash issue. The problem is that S3 doesn't consider the slash as part of the rewrite data unless something comes after it.
Ultimately, my number one suggestion would be to go with a different service that allows you to install a Server App like Nginx or Apache. Others have agreed that redirections set up through a server app are the way that they feel the most comfortable that link equity is being passed.
If you're dead-set on S3, which I would understand as the load times are crazy-awesome-insane, I may have a solution for you soon. Our dev team is working on a script for Jekyll + S3 sites that will essentially create extension-less files (i.e. example.com/contact) that contain meta refresh + rel canon.
The script will use a list of desired redirections + rules that is structured the same way an htaccess file would be. I can't speak to how it will get past S3's default 302ing yet, but I know that it will use CURL. Look for a YouMoz post soon from me!
Anyways, I hope my notes here help! I'm gonna try and make that post soon after the script is created. Just as a last note, in taking a look at your site I noticed that a lot of the internal links on your homepage don't have the trailing slash in them. I would definitely start there and add those slashes, and perform a "submit page + linked page" to Webmaster Tools after!