pci pins short

Hello All

Summary:
I'm looking for confirmation that I have correctly analysed a problem
I had some time ago, and face again.
Can I short pins out on an adapter of the pci family if the backboard
of the PC is out of alignment (not perpendicular) with the motherboard
by about 0.025 inches?
My number crunching begins at paragraph 2.

Details(DIYS PC):
After putting the motherboard with cpu, cpu cooling unit, and ram onto
a removable (slide in/out) tray and just before sliding it into case.
..
..
..
1.One must pay extra attention when starting to slide the PC tray into
the PC chassis as the tray must fit into rails provided by the chassis
and it is easy to start with them slightly misaligned. If the
resistance to motion suddenly increases or things look a bit odd as
they are going together, it is probably because some alignment is
incorrect. The gauge of this Aluminum is not the case's best
feature. It is too easy to warp alignments and a big pain to repair
the warp once it is established (so many other things you could be
doing with your time). Lest you be tempted to postpone repairing
alignment problems consider one of the consequences.
Remember your geometry. Recall how squares, rectangles and boxes of
all sorts have straight edges that are either parallel or they
intersect at 90 degrees. Misalignment results in intersections that
are not a true 90 degrees. Consider a rectangle snuggly embedded
inside a larger square. Corresponding edges are parallel.
Corresponding corners are congruent. That of course is a model for
how adapters should fit inside the PC case. Adapters are rectangles
with a utility bumper attached at the back. The utility bumper is
designed to be fastened at the top to a ledge in the case back panel.
The bumper is parallel to the back edge of the adapter. Then, at the
top, the bumper rear edge vertical run from bottom to top, makes a 90
degree turn to horizontal and runs horizontal onto the back panel
ledge. That horizontal part of the bumper is just long enough to cross
the back panel ledge. Both the bumper horizontal part and the back
panel ledge are tapped to receive a screw to fasten down the adapter
and eliminate vibration and air leaks.

2. Of course these adapters all have pins perpendicular to their
bottom edge that must mate with grooves in the receiving slot. These
pins are packed fairly tightly, about 20 per inch. Here is where
alignment becomes critical. At 20 per inch, the actual width of the
metal pin is about half that or 1/40th of an inch = 2.5% of an inch.
The length of the pin or the depth of the groove is about half an
inch. If the misalignment is also 1/40th an inch or greater these
pins are very likely to short out against the adjacent groove.
Manual pressure upon the adapter while seating it in the slot may seem
to correct this misalignment, but the forced alignment will probably
create tension that will, over time, cause a short (or an open in the
case of the rear pin). The more work that is done between the time the
misalignment occurs and the time it is detected, then the more work
that will have to be undone and repaired after it is detected.

Thank you.

Bob