Doppleganger PC

These are my house rules for Doppleganger PC's

Since birth, Dopplegangers are able to mimic any humanoid in their
presence between three and ten feet tall by *scanning* them.  This scan
informs the Doppleganger's subconscious of where organs are placed, how
they work, as well as density and composition.  (think of it like a Star
Trek Tri-Corder).  This is a fledgeling version of the ESP ability theyr
eceive later in life (once/day/level starting at 10th).  The shape
shifting is biological in nature and is 90% accurate and cannot be
bagically dispelled, though "true seeing" will work normally.  Bein
biological in nature, a doppleganger may not attain magical abilities
(such as a medusa's gaze) but it will allow for flight (aaracockra,
kenku, avariel, gargoyle, etc.) and in some cases infravision (DM's
discretion).  Equipment and clothing is also reproduced (in a non
magical version if the items are magical) but will crumble to dust in
1d8 rounds if not within 3 feet of the doppleganger.  At tenth level
they may cast ESP once/day/level by force of will and only for the
purpose of assuming someone else's form.  Dopplegangers are immune to
sleep and charm based spells and effects, as well as immune to any
psionics that target their mind.  They receive no adjustments to their
ability scores and any class is available to them save psionicist and
cleric/priest/druid/paladin