The noise is the reversing valve switching and the pressures rapidly changing while the compressor is running.
Sometimes you will even get a little hiss when you switch between heat and cool with the system off (compressor not running) depending on the configuration of the particular system.

Time delay is normal just like on a standard a/c but does not come into play normally during defrost since the unit will be running.

85 would be within the realm of normal... but that is not a diagnostic tool as it is meaningless without other information.

__________________
Jim Luttrall
Mr. Inspector.net, Inc.
Allen, Texas 75002