Answer: Each site catalog has its own terms and conditions. It is really pointless to comment on them. Nothing is going to change anyway. It is done in this way so that site catalog administration can sort out qualitative websites from non-qualitative.

But if the site catalog is reliable, it will always publish websites with manual moderation. Here is an example of a catalog you can refer to: http://www.dmoz.org/

You can find lots of websites from free web hosts on the pages of this catalog, because it is believed there that the content of the website defines its quality and not the hosting it uses.
That is why you need to post your websites in catalogs that are moderated. They should be site catalogs with qualitative resources, which do not set limitations on free or paid hosts.

Answer: Certainly, you can upload your own robots.txt file via the File Manager or an FTP client. However, we strongly recommend not to do this as the default robots.txt file is adjusted so that search engines could index your site the most qualitatively, i.e. robots would see only the pages of your site that contain some information and would not see any technical pages (users’ login page, registration page, etc.).

Answer: As a result of struggle with people who use the system to create doorway pages we temporarily block website indexing by means of the "robots.txt" file. Such blocking also helps not to spam the index of search engines with empty sites. You shouldn’t worry about that, blocking is automatically disabled in 30 days (it should be enough for you to fill in the website with content, so that search engines could index it in the best possible way) or if the site has some minimum number of visitors (the exact values are not disclosed in order to prevent abusing).

Promotion of a website should start not with its submission to search engines (search engines will find your site anyway), but with reading the "Site Promotion" section (the link is on the main page of the Control Panel).

Remember, we are also interested that your sites were interesting and popular, therefore EVERYTHING that we do, we do for your advantage.

Answer: When search bots visit your website, they look for this file in the first place. Robots.txt is a text file. It is located in the root directory of the website and contains instructions for the search engines regarding this website. A webmaster can set indexing parameters either for all search engines at once or for particular engines separately.

In the majority of cases, the default robots.txt is more than enough. If you need it to be changed, it can be done by means of a text editor. Do not forget to check your robots.txt after making the changes. It can be done by means of Google Webmaster Toolbar.

Useful link:
uCoz Community Forum

Answer: PR (PageRank) is one of Google search engine algorithms. It is calculated for each document separately. This parameter does not effect the search engine results. As a rule, it is used as a parameter to evaluate the importance of a website/webpage.

Useful link:
Wikipedia

Answer: As a result of struggle with people who use the system to create doorway pages we temporarily block website indexing by means of the "robots.txt" file. Such blocking also helps not to spam the index of search engines with empty sites. You shouldn’t worry about that, blocking is automatically disabled in 30 days (it should be enough for you to fill in the website with content, so that search engines could index it in the best possible way) or if the site has some minimum number of visitors (the exact values are not disclosed in order to prevent abusing).

You can check the date of your website registration on the main page of Control Panel in brackets, right after the name, which you have used to register the website.

If you still want to unblock the robots.txt file for your website to be indexed sooner, you can pay for any service which costs more than $2 and the quarantine will be over.

Useful link:
uCoz Community Forum