How to have more control of FTP?

I have DA installed on my dedicated server, which host some files over FTP. There are two things I wan to do:

1. For a ftp user that I create (with his account and password), how can I limit him so that he can only download but cant delete the files in the directory I pointed him to log in?

2. How to limit the number of lines people are using to download the file? For example, people can use Flashget to open 10 lines over the file on my server, i would like to limit them to only using 1 or 2 line. I have proFTP installed on my linux machine, and it;s centOs, can someone help?

Thanks.

See:
http://www.proftpd.org/docs/directives/linked/config_ref_AllowOverride.html

Proftp has a similar system to apache's .htaccess files.
You should be able to control the things you want through one of those .ftpaccess files once you enable the override in the main config. Although there is no way to set it from within the control panel.

Thanks...um...but could you explain wat should i write in .ftpaccess and where should i put it in? I cant understand the page totally.