(Plugin: Role Scoper) Need Setting Assistance, please

I am new to RS and Word Press and two days under my belt so far. I am sort of stumped on a few configuration settings.
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This is what i am trying to do in a nut shell:

The front end content is to be basic to allow the general public an opportunity to view a few items. One of the items is to allow a post for the general public to add comments, so they can interact with existing members.

I actually want to allow the general public to post comments to this one post. Although there can be spam with this idea it would be hard for the website admin of the volunteer group, the site is for, to login on a regular basis and moderate the posts. It is lazy I know, but they are an older woman’s group with little to no experience.

Then once a user logs into the site they should have access to almost all of the categories and posts. They should be able to post comments, edit comments, and such. I would like for their posts to not be moderated as well because they are already logged into the site. If there is anything offense I have instructions for removing that post.

The only other want in this situation is to allow one of the default roles the ability to modify certain pages as they are board of directors and tasked with updating items on their respective pages (i.e. meeting minutes, photos, etc).
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So that is the goal and what i have done so far is:

I was able to add Post Reader permissions to all five WP groups except for a few items such as photos, the general public post, contact page, about, and the calendar. This limits the general public from seeing the general membership content which is visible when a member is logged in to the site.

That is about the best I was able to do so far and I have a few issues, which I think could be resolved with some help.
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The issues so far are:

When someone is not logged in to the site they can navigate to the post from the sidebar and get to a point where they can type in data on the comment section and when they click submit they get a 500 (Internal Server) Error.

When a user who is logged in tries to post a comment they get a 500 (Internal Server) Error as well. When I login as the administrator I can post fine without any moderation.
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Currently installed:
Word Press 3.1.1 (scared to update to 3.1.2 right now)
Akismet 2.5.3
Grand Flash Album Gallery 0.60
My Calendar 1.8.7
Peter’s Login Redirect 2.0.0
Register Plus 3.5.1
Role Scoper 1.3.31
Ultimate Google Analytics 1.6.0
WP-SpamFree 2.1.1.1
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Any thought on how to get to my goal of configuring the site?

The site is http://restonnewcomers.org/index.php