For most folks; the "strapped to the tank" skidplate works well. You
*have* to drop the tank (which is usually "strapped" in place itself) to
mount the plate. It's not that big of a deal; run the tank almost empty
and pull the hardware. I'm not familiar with the 2005 F150; but I
wouldn't be surprised if it was plastic. If so; you might be looking at
30 pounds; but I'll bet it's less.

If you don't want to drop the tank for installation; you are wandering
into custom and/or full-belly plates. I don't think you want to go there
on price or installation.

As far as "all that electric stuff fails sooner"; you are about half
right.  I've lost 1 of the infamous "TFI ignition modules" on my '88 BII
in near 300k miles. Substitute points and I can guarantee that in the 40
or more sets of points that there would have been at least 5 short-life
or dead-fails out of that.   I'll admit; when some of the larger stuff
goes bad it is *expensive*.  Maybe I've been lucky; but the only
electronic or electrical things that have gone bad are:

plugwires (expected)
bulbs (expected)
o2 sensor  (expected)
throttle position sensor (expected) and is mainly mechanical anyway
speakers (expected) and not all that bad; just new ones sound better.
same TFI above (expected)
blower motor (expected)
dimmer/turnsignal switch (column mount) (still expected)
factory radio/tape (started drifting off station-or-I really wanted
CD/MP3 ;} )

What's still working?

window motors (one replacement gear fix but not the motor)
the "computer" itself
door solenoids
coil
almost all the rest of the wiring etc (but see below)

I will admit that I do have to replace the damned fuse block; Ford's
cheesy plastic has cracking problems and it's held in by tiewraps and
ductape.  The dash headlight switch and the harness socket need
replacement (the infamous burning headlight switch recall that Ford says
"doesn't apply to the BII") soon as I've scraped and squeezed the
contacts too many times.

What I've seen of later vehicles is pretty much the same. There are some
horror stories (true) about rigs that have gone thru 3 or more ECUs
(Engine Control Units) or whatever the mfr calls their black boxes.
There will *always* be those stories. Like all horror stories; one
incident can end up sounding like thousands.

I'll admit I'm an electronics tech .. and I had a lot of trepidations
about trusting my vehicles to them damned electrons for years. I'll also
admit that I think that there is too much of the new systems that can't
be maintained by the average owner anymore. That carries over into even
qualified mechanics anymore. To be current; a decent mechanic now has to
attend (or otherwise achieve) training far more often than in the past.
(any mechs want to step up and give examples?)

One thing has occurred; the average mechanic now has a much better
understanding of electricity now than was seen 10-20 years ago. I've got
my own horror stories about convincing mechanics that a bad alternator
diode(when hot) can make a certain two-way radio model change channels
unexpectedly. A relay that shows voltage (with a test light) on both
sides of the coil *doesn't* drain the battery. (it was the hood light)
Putting a fancy 20A "aircraft" circuit breaker in the dashboard and
running the hotwire thru a bare hole in the firewall to the battery is
worse than no breaker as it's very false security.  I still see some of
this; but about 1/10th of "back then".

Sorry for the rant.. but I had to deal with a "factory trained
automotive technician" last week who was blaming the two way radio I'd
just installed in a new Toyota Prius for an engine heat sensor problem.
Yes - it's possible. I wasted six hours running a pile of specialised
test equipment "sniffing" for "bad radio". When pulled; the sensor was
physically cracked at the probe end.   ARRGGHHH ~~!!