Hello Ken,

Coupling to other antennas is very light, so the position you mentioned is
no problem I think. It needs a little height to work proberly, the minimum
is about 3 metre.
Coaxial cable length is no problem. I have had reports using lenght's up
to 100 m. Depending on the length of the cable inside the house, local
noise from the house will travel along the braid of the coax up to the
antenna.
To get rid of it, it is best to ground the shield of the cable at the
bottom of the mast or before it enters the house. I use both methods,
which results in a very low noise floor, though the antenna is only 6
metre from the house. Vegatation does not need to be a problem either;
mine is mounted up the stem of a magnolia tree!

I hope this helps.

Best regards,
Roelof Bakker, pa0rdt