I will attempt to answer question 4. Someone more knowledgeable
can always correct me if I am mistaken.

rwx only for the owner and nobody else should be the general guideline.
However,

1.  If you want people to be able to go to your public_html directory and load
up your index.html file to start their browsing, then your home directory and
your public_html must have x permission for all.  Same idea for the
sub-directories. As well, files which you want others to be able to read should
have r permission for all.  There is no need to give r permissions to
directories, unless you absolutely need to display a listing of all your files
in a certain directory. Of course, you could also create such a listing
yourself in an html file. Purists seem to think that giving r permissions to a
directory in a http situation is a security risk.  In fact, there are web
servers that won't allow directory listing at all.  One can always experiment
to see what works and what doesn't.

2.  It was thought by some that in order for .forward to work properly one
would need it be world readable, i.e r permission for all.  However, my
.forward was only readable by owner only and it still worked.  I just checked
my .forward and I see that it has r permission for all, so I guess Barkley must
have ran a script to add r permissions to everybody's .forward, just in case
there is a problem. Making .forward readable by all is not such a big deal
unless mail is being forwarded to some exotic places. The other mail files do
not need to be rwx by g (group) or o (others). Only rwx by owner. Barkley might
have already ran a script to make sure your mail files/directory are only rwx
by owner only.  One can use chmod go-rwx to remove permissions and chmod go+rwx
to add.  Details can be found using man chmod. There are various combinations
one can use.

3.  hidden files like .cshrc do not need to be readable by anyone else beside
owner.  As you can see from parts 1 and 2, nothing in your home directory need
to be r or w or x by anyone else other than owner. The only exception are files
in your public_html directory and your home directory should be executible i.e.
x permission, by all as was explained in part 1.  You can use    umask 077
in your .cshrc file to make sure the proper permission, i.e. rwx by owner only,
is set whenever you create files.  Just make sure you are indeed running tcsh
or csh. Some people have a .profile which may change their default shell to
something else.