"If I am the administrator to my-domain-name.com, how is it that I do not have permissions to delete certain folders in my "htdocs" dirrectory?"

You are administrator to my-domain-name.com, but you are not administrator to the server.

The web server is running under a user called "webadmin". Your folders are owned by the user "myusername".

User "webadmin" cannot write into the folders owned by user "myusername", unless the file/folder permissions are set as world-writable.

When you are installing Joomla via http://www.my-domain-name.com/.../install.php for example, please bear in mind that the web server, i.e user "webadmin", will run the script. If the script says, "create a folder called 'com_simple_review' in this 'htdocs' folder", you need to give enough permissions. This can be done by setting the folder "htdocs" as world-writable, so that user "webadmin" can write into the folder "htdocs" owned by user "myusername".

When the folders (such as 'com_simple_review') are created by Joomla, i.e. by the web server, i.e. by the user "webadmin", these folders will be owned by user "webadmin". User "myusername" cannot delete folders owned by user "webadmin". (Remember: you are not admin to the server.) But since these folders are owned by user "webadmin", they can be deleted by user "webadmin", i.e. by the web server, i.e. by Joomla.

In other words, consistency needs to be maintained. If something is created by Joomla, it was to be taken out via Joomla.

When you are using FTP to upload something, you are doing so as the user "myusername". Any files and/or folders created in an FTP session will be owned by user "myusername". As mentioned earlier, user "myusername" cannot delete files/folders owned by user "webadmin". And vice versa. But user "webadmin" can write into your "htdocs" folder if you set it as world-writable.

With any standard compliant FTP program, for example Filezilla from http://filezilla.sourceforge.net/, you can set the permissions yourself. The picture below will show you how to set "htdocs" as "world-writable".