followup: typos, formatting and wording improvements

followup: typos, formatting and wording improvements

fix some typos like s/seperate/separate/ passhtrough, ...

Reword some sentences, try to reduces commas per sentence (while I
like them, others don't and they entangle your mind when reading a
bit).

Try to improve formatting, adding some emphasis on abbrevations or
other important things. Ensur all abbrev. are writen uppercase.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>