The only chronic problem I've noticed with our '05 Murano (31K miles)
is with rattles in the front dash behind the radio somewhere.

I suppose we've learned to deal with the blind spots which, I agree,
are definitely noticeable.  However, I think we knew what we were
dealing with before we bought it.

I haven't noticed any play in the electric seats...I'll have to check
that, though.

My Murano (03) is sitting in the garage with 117K, so safe to say it's had
some "over the road" experience.  Regarding your questions and comments:

1.  Once you're comfortable using the concave mirror on the passenger side,
the blind spots will no longer be an issue.  If the mirror is adjusted
correctly, the ONLY blind spot will be to your immediate right, which can
easily be viewed through the passenger or rear seat passenger window.
However, not being used to using mirrors can highlight the undeniable blind
spots in the design of the cabin.

2.  I had to replace my front struts which were totally shot at around 60K,
however until the final stages of failure, I did not have any noticable
noises.

3.  I've owned 13 Nissan's, and ALL of them did this in cold weather
(especially) after sitting a few days.  Honestly, I wouldn't worry about it.
I logged over 100K on all of mine, and never had a engine issue of any type.

4.  More recently I have noticed the driver seat making a metal against
metal noise when I jostle the seat such as over bumps and rough road.  But I
can't say I can actually feel it move - it's more of an audible thing.

The only issues I've had with mine are as follows:

1.  Front struts
2.  Driver Power Window Track...  had to replace everything including the
motor.
3.  Heavy rust on some components - to the extent the screws in the rear
license plate holder cannot be removed.
4.  Recently developed a minor leak in the rear seal.  Labor will be
$1100.00 and cost of parts around $5.  I'm not planning to make this repair
unless it worsens.  Right now it's averages about 1 quart low when I'm ready
for an oil change, so that's no more than most cars burn.

Willy