Trying To Get A Multisite Setup Off the Ground

I hate to ask another question regarding this topic, but my newbie-ness has prevented me from applying similar situations to mine. I'm not sure which path I should be taking, so I am hoping I can get some clarification as to which option(s) are viable for me. In short, I am trying to determine the best way to setup a network of blogs on subdomains with my present hosting environment. I've outlined my situation below, followed by my specific questions. Thanks in advance for your help.

I. My Hosting Environment
.....A. Shared host (HostPC to be exact) with DirectAdmin on Apache servers
.....B. No shell access and just one database (I went cheap here)
.....C. DirectAdmin features the ability to create subdomains and has a "DNS Management" option

II. Concept I am trying to achieve
.....A. Structure
..........1. The main site will be www.qweblogs.com which will feature content from ALL of the subdomains.
..........2. For purposes of discussion, the subdomains will be:
...............a. test.qweblogs.com
...............b. test2.qweblogs.com
...............c. test3.qweblogs.com
.....B. A network of blogs on subdomains.
..........1. At MINIMUM
...............a. Each blog will have the same layout (modules, theme structure), but different colors and headers.
...............b. Only 1 author across the blog.
...............c. Users, with one registration, can comment on blog posts on each different site.
...............d. MINIMUM, blog posts on each subdomain will ALL appear on the main page.
..........2. IDEALLY
...............a. I will be able to have the ability to post to select subdomains (post appears on test and test3, but not test2)
...............b. Additional flexibility with user roles to allow others to post content in a fashion described above.

III. My Thoughts
.....A. The Domain Access module sounds like the best option to me.
..........1. However, it is noted that it may not work in shared host situations.
..........2. I have indeed tried installing it hoping that it might work (more on that later), but my attempt to bring test.qweblogs.com to life did not work (Error Message: "http://test.qweblogs.com/ is not responding and may not be configured correctly at the server level. Server code 403 was returned.")
.....B. With regards to the above, I am clueless when it comes to this DNS stuff.

IV. What I tried
.....A. I created the test.qweblogs.com subdomain in DirectAdmin
.....B. I tried to understand the DNS settings in the INSTALL.txt of Domain Access, but I don't get them at all really. I looked under the "DNS Management" page in DirectAdmin and all of the IP address values were the same for all of the domain and subdomain options.
.....C. Considering 'B' above, I decided to enable the module and see if by chance it worked.
.....D. Everything seems in working order except, creating test.qweblogs.com did not result in the creation of anything but an error message on the "Edit domain record" page saying: http://test.qweblogs.com/ is not responding and may not be configured correctly at the server level. Server code 403 was returned.
.....E. The error message when typing test.qweblogs.com into the address bar reads:

Forbidden

You don't have permission to access / on this server.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
Apache/2 Server at test.qweblogs.com Port 80

V. Questions
.....A. Does anyone have first-hand experience with identical/almost similar hosting situations trying to achieve what I am going for? I think my DNS ignorance is the problem since something is wrong server wise, but . . .
.....B. Is Domain Access really the best option for me? Is it even possible for me to use it in my hosting environment?
.....C. Considering 'B' above, is the core multisite setup or something like Organic Groups, etc. something I should be looking into?

Please let me know if there is any other information that I can provide to help you help me. Thanks.