2.
Probably best to illustrate how ifconfig handles netmasks too.
3.
Coming from GNU et al. toolsets, the naming pattern of procstat/fstat/vmstat/netstat/kldstat/sockstat/iostat is not obvious when only sees them presented as piecemeal equivalents.
It's some combination of the [b], [x], [y], and [z] keys that I don't remember off the top of my head. I no longer use top, as I wrote my own tool, so don't need to keep it memorized any more.
It turns out that I started the procstat command before the Big Gap, but didn't finish it. It didn't actually work and was just a placeholder. So I've made it do things.
It's not a complete clone of the FreeBSD one, but it doesn't set out to be (It has a different output format and because of that post-processing can be done with shell scripting and ordinary tools like awk.), and some of what the FreeBSD one does isn't cross-platform anyway.
http://jdebp.info/Softwares/nosh/guide/commands/procstat.xml
JdeBP