Thanks for you advice and help ahead of time

I have a website that has been on the internet for almost 10 years created in "Microsoft Frontpage" with over 900 pages. Currently in Google Webmaster tools it shows up as 2 domains and 3 sitemaps:

http://www.example.com

example.com

hostedsitmaps.com

Furthermore, since we were having hard to placing the xml sitemap on our site(Frontpage Issues) we decided to hire pro-sitemaps.com to create, host and upload the xml file which they did. Thus, I have another site hostedsitemaps.com on our webmaster tools for the site.

Hosted sitemaps shows:

900 urls submitted 800 Indexed.

Crawl errors and Search queries: No data available

http://www.example.com shows:

889 URLs submitted 1 URLs indexed.

Crawl Errors: 14 Soft 404 796 Not found

Search Queries: 8104

example.com shows:

889 URLs submitted 1 URLs indexed

Crawl errors: 48 Soft 404 91 Not found

Search Queries: 8104

My questions and need for help are as followed:

1. Why are our domain based sites in webmaster tools ( example.com and http:www.example.com) showing only 1 URL indexed while the hostedsitemap has 800 indexed?

2. Should we have 3 domains configured for this "one" domain in Google Webmaster tools?

3. Should we eliminate/delete the hostedsitemap from webmaster tools completely and take off that XML sitemap?

4 Does having example.com and http://www.example.com impact web ranking?

5. Any other thoughts or help in this very complicated matter for us.

Thanks.