Articulate vs. Captivate - 508 Compliance (ASL Sinage Videos)

The company I work for is looking to switch from Adobe Captivate as their agency standard to Articulate Storyline but had a few questions regarding Accessibility.  Since we're a gov't agency that provides services to people with disabilities, this is our PRIMARY concern. I'm hoping to find answers.

• ASL Video - We have American Sign Language videos that we put into our captivate courses either in the TOC or on the slide as slide video.  What options do we have with Articulate to do something similar?  
• Closed Captioning - Looks like this is possible in Storyline using the methods mentioned in this video:  http://www.articulate.com/support/kb_article.php?product=st1&id=1keancorydu4
• JAWS (and other screen readers) - Can we do alt tags (descriptive tags) on images?  How well does this work in practice?  Anyone have hands-on experience with this?
• Keyboard Navigation - Can we use shortcut keys to activate buttons and other navigation elements?
• Is it possible to synchronize a slide video with closed captions?  Captivate has this feature, but I'm not seeing it in Storyline.  Is this possible?

I've read the 508 articles here:

http://www.articulate.com/products/storyline-section-508.php

and here

http://www.articulate.com/support/kb_article.php?product=st1&id=te6jcgjd47yv

But it's always good to hear from the community about these aspects as it applies to real-life use and experience.

TIA,

Jim Leichliter