To run proxy checker you can use docker image deademo/proxy_checker
Just run docker run deademo/proxy_checker
To check your proxies just put them after, like this:
docker run deademo/proxy_checker http://10.11.12.13:7654 http://anotherproxy.com:7653 someproxy.net
Hint - you can check your proxies from local file:
docker run deademo/proxy_checker $(cat /path/to/file/with/proxies.txt)
You can enable progress bar by using -pb or --progress_bar argument, example:
docker run deademo/proxy_checker -pb
or
docker run deademo/proxy_checker -pb http://10.11.12.13:7654 http://anotherproxy.com:7653 someproxy.net
For other arguments use --help argument
No, you can not. Right now there no ease-to-use way to change checks.