Hi Rod,
I will try address the 2 questions I see here.
1. Is an "index stack" bad for your site.
2. How do I optimize my site.
1. Index Stack, okay to be completely honest I have never heard the term before. However, with the link you provided I was able to understand what you mean. In such case you have taken the content of your sub-pages and placed them directly on your home page. Is this bad.. YES!
The reason why this is bad is because it is creating duplicate content. This is bad because the page that should be ranking for X content is now competing with your home page for these rankings. Your home page should be about your business and services, what you do, and how you do it. The sub-pages are your re-enforcement they support the content stated on your homepage.
Imagine a beautiful hotel. The outside is adorned in the finest materials of the time, well maintained and awe inspiring. A equally impressive doorway beacons you to come in. As you do, you find yourself in the lobby. Well placed pristine signs detail some of the hotel's offerings, private gym's, hot tubs, saunas, massage, 5 star dinning, dance halls, and judging by the impressive lobby you have no doubt these offerings will be spectacular.
In this example the lobby is your homepage an impressive list of the offerings guest will find inside. What you don't see is a middle-aged fat man sprawled out in the lobby getting a massage. Which is what your index stack is doing.
2. How to optimize (fix it). To fix this you'll want to structure you home page to be about your business, and services. High level overviews of what you offer, with strong brand placement.
The purpose of the homepage is to make it clear what you do, how you do it, why people love it, and in general more about your brand. The purpose of your inner pages is to completely detail the particular service or products, with call to action to convert interest into money.
I would remove the internal page content from the homepage, and focus again more on an overview. Essentially cut out everything between the Hunting & Gathering Club, and the Call to Action "There's a Southern Whitewater Experience for everyone". Beef up the links to the internal pages by making them look more attractive and obvious.
There are other things that may need addressed as well, but I hope this answers your primary question,
Don