mcrypt can be installed in PHP 7, it's just not there by default on a lot of hosts. Based on what I've read, I wouldn't use it if you need very tight security, but if you don't need that level of security, you might ask your host to install it for you, the installation is very simple.
Are you using FileLister 1.1.7?
Do you care if things are encrypted or not?
No, I'm running version 1.1.1-pl (I was under the impression that 1.1.1 was the most recent version). Where are you seeing 1.1.7?
Encryption is not mandatory.
You're right. 1.1.1-pl is the current version. Either I misread it, or I was hallucinating.
i've got a site running that uses the filelister extra.
as it stands right now I don't have any issues with it. Do you get any errors in the log?
Addict since 2012....
I've happily used "FileDownload R" on projects ages ago, no idea how well that still works these days tho.