No offense but I think /sethome should be restricted similar to how /lock and /unlock is right now.  At the moment it is possible for people to /sethome inside other people's faction regions even if they are not part of the faction in question.

So 2 options exist.

1) Either modify the existing or code a new homes plugin to respect faction regions and only allow them to set home if one of the following conditions exist.
-- It is in the wilderness where there is no faction claim
-- It is in an alliance/neutral/truce faction claim
-- It is in your own faction claim

2) Restrict the use of /sethome in the faction world and only allow it in the non-faction world.  Existing /home command should be able to still work in order to allow it to be used to quickly get back to the non-faction home even when in the factions world or to be able to use an existing /home before the restriction has kicked in.  This option is available because /f home is available which will get you to your faction's home point where ever that ends up being.

Personally I would prefer the former as it would still allow a proper use of the home command and people wouldn't be able to use it to set a home point inside someone's base.