1: Is it now safe to use in tails?
2: Mentioned in some installation guide to run this command directly after install: > chmod a+x /usr/local/bin/youtube-dl
What does it do exactly?

1: Is it now safe to use in tails?
2: Mentioned in some installation guide to run this command directly after install: > chmod a+x /usr/local/bin/youtube-dl
What does it do exactly?
Sorry, installing additional software is possible, but not supported here. Wrt. the
chmodthing, I suggest you read some documentation about the Unix basics. Other than that,youtube-dlandcliveare in Debian.