Here are some article excerpts that support much of what I have been saying
(emphases mine):

Bunions
http://www.joshuakaye.com/topics/bunion.html#comeback

Q: What is a bunion?

A: Bunions are primarily a HEREDITARY CONDITION and MOST OFTEN PROGRESSIVELY
WORSEN THROUGHOUT LIFE. They can affect anyone, although they are most
common in women. BUNIONS WILL USUALLY BE VISIBLY PRESENT FOR MANY YEARS
BEFORE THEY BECOME PAINFUL. A change of shoes, activity, or body weight can
cause previously non-painful bunions to become painful. 

The exact cause of bunions is unclear. SOME OF THE CAUSATIVE FACTORS INCLUDE
HEREDITY, FLAT FOOT STRUCTURE, LIGAMENTOUS INSTABILITY OR LAXITY, MUSCULAR
IMBALANCE WITHIN THE FOOT AND BIRTH DEFECTS. IMPROPER SHOES DURING CHILDHOOD
MAY CONTRIBUTE TO THE FORMATION OF BUNIONS, BUT THIS IS UNCOMMON.
INAPPROPRIATE SHOES DURING ADOLESCENCE AND EARLY ADULTHOOD MAY AGGRAVATE AN
EXISTING BUNION FORMATION."

Q: Do bunions ever return?

A: NO SURGEON CAN GUARANTEE PERFECT RESULTS. Unfortunately, if the wrong
procedure is performed, the recurrence rate can be quite high. Many of the
micro-surgeries and laser techniques have a high recurrence rate because
they generally cannot accurately realign the bones. These types of
procedures have become less popular recently due to the incidence of
recurrence as well as other problems.


Overlapping and underlapping toes
http://www.foothealthcare.com/html/footprobs/problem/overlaptoe.htm

Toes can sometimes overlap or underlap the other toes and can be the cause
of constant irritation. The cause of underlapping or overlapping toes is
generally unknown. They may be caused by an imbalance in muscle strength of
the small muscles of the foot.

If deformed toes are flexible, a simple release of the TENDON in the bottom
of the toe will allow for them to straighten. If the deformity is rigid,
surgery may be needed to remove a small portion of the bone in the toe.


Overlapping Toes Can Cause Pain, Problems
A Monthly Foot Fact From Foot.com
http://www.personalhealthzone.com/overlappingtoes.html

Are your toes pressed together until they overlap, causing irritation and
making it difficult to walk without pain?

According to Dr. Suzanne Belyea, D.P.M., C. Ped. and medical director of
Foot.com, overlapping toes are one of the most common causes of forefoot
pain in people of all ages.

"In childhood, the most common occurrence is the overlapping of the fifth
toe, caused by a high arch or FLAT FOOT," Dr. Belyea says. Children with a
high arch put more weight on the outer part of the foot, causing pressure on
the toes. The way a flat foot functions can cause hammering of the little
toe, leading it to cross over the next toe. In these cases, orthotics can
help correct the problem.

In adults, poor-fitting shoes, the cause of so many painful foot conditions,
are also usually the culprits [actually, they may contribute but are not
likely to be the main culprit]. Footwear with a constricting toe box puts
pressure on the toes, squeezing them together so that eventually, they begin
to overlap. The problem can also start with BUNIONS, protrusions of the end
of the big toe's long bone, caused when restrictive toe boxes force the big
toe inward. This contributes to overlapping of the inner toes.