Hi insk,

1. if you mean use it in the <iframe>, then it will work.

2. You can create a virtual directory under your site and save the upload file into this virtual directory. The virtual directory can point to any location or remote server, just ensure that your site has the write/read permission of the folder you set for. 

3. The progress bar is support by default, do you get problem with the progress bar on your site?

Regards,

Ken