1. I am not a mechanical engineer. What follows is my opinion only.
That being said, I'd ask why you are pursuing an elevated guy point
for the house guy. The mast will have to support a large bending
moment in the mast itself. I'd suggest keeping the guy straight all
the way from the tower to it's anchor point. You'd need to make a
weatherproof connection through the roof, perhaps using a section
of steel. Then continue the guy, at the same angle, down to
an anchor point in the attic. This should all be looked at
by a 'real' engineer...
Also, the tower you propose is very similar to the one in our
article. Unless you are planning more than 6 square feet of
antenna, you don't need guys at all, as long as the bracket support
-Tony, K1KP, firstname.lastname@example.org