1. The answer depends on what service your server is providing. If it's a web server, you can use the "curl" or "wget" tools to retrieve the files; they have lots of options to control which files are downloaded. If it's providing file service, you can use tools like "cp" and "rsync". And you can also use "rsync" even if it just provides ssh service.
2. If you google "linux make video from images" you'll find lots of options.