if &sub is looking old style to many monks (not me, and is quite good if you do not use prototypes at all and if if you are aware that ⊂ will call &sub(@_); behind the scenes)

I disagree, it is not "quite good". Or I would at least phrase it the other way around: It is really bad unless you really know what you're doing and really need that feature. Otherwise, simply don't use that obsolete syntax.

For the rest, I agree that it is usually better to use a module with use rather than require.