MRASM BKEP was a sub-variant of MRASM, which itself was a subvariant of Tomahawk. AGM-109H (Photo 4) should also be distinguished from the AGM-109 variant proposed to compete with the Boeing AGM-86 (Photo 3) and the shorter tactical AGM-109L (Photo 2). 
Developed by Sperry-Douglas, like the first one, the second Sparrow was primarily intended to provide a better guidance system to allow for successful intercepts of maneuvering targets, or from other angles besides directly ahead or astern of the target.
After the success of the AIM-7, and the expansion of AIM-7 carriage from F-3B to F-4 to F-15 and F-16, AAM development has become largely uncoupled from airframe and fire control radar development. This has been mostly a positive, but there are some negative aspects as well. 
Though the development history of the AIM-9E is somewhat murky, we have some information.
The most common issue with HMDs of the 1970s and 1980s was weight. Kaiser Electronics understood this problem, and set out to not only lower the weight of the helmet to below that of a conventional flight helmet, but also to adjust the center of gravity to be closer to the neck. 
The higher resolution images provide some interesting details about the first one. 
Taxiing out onto the runway, they hold their brakes as they let their engines spool up. At full power, they engage their afterburners, and wait. 
The first point to cover is radar stealth. Stealth is a bit of a silly term in some ways. A better term for this is "very low observable." What that means is that effort is made to reduce the radar signature of the aircraft, often combined with infrared signature reduction.
Even before the American entry into Vietnam, Forward Air Controllers began operating in the theater. These were necessary to coordinate air support to ground troops in the dense jungle, which prevented pilots of larger, faster aircraft from effectively spotting their targets. 
A Browning tilting barrel action is a short recoil action where, under recoil, the barrel unlocks from the slide and the rear tilts down on a pivoting link.
The first thing to clear up is how to identify whether or not these IRSTs were fitted to an F-4. First, does the aircraft have a chin pod, and second, is the tip of the chin pod reflective or dull?
The Sparrow I was a radar beam-riding missile. This meant that the missile would try to center itself within the radar beam during flight, which was locked to the gunsight's position. This can be seen in the spiral path flown by this Sparrow I.
Unfortunately, few images of this missile exist. However, what does exist helps greatly in identifying what it was and what went wrong. What also helps is a few identifying details on the R-3S that came out of it. 
The first issue to cover is that he portrays M855A1 primarily as an "eco-round". This is technically true but it was not the primary motivation for its development. Issues with M855 such as poor performance on target at range initially spurred the development of M855A1. 
What can be seen is the A-1 topping the charts in all theaters in which it saw service. The F-100 was not far behind in North Vietnam due to its low speed and thus "vulnerable time" to radar-directed AAA fire or other various types of ground fire including small arms. 
The first place to start is most definitely with the deficiency that generated the requirement for what would become the F-X program.
Many elements between full-caliber armor-piercing shells and AP bombs are shared, including charge/mass ratio, AP cap design/thickness, oblique angle penetration, and utilization of base-fuzes.
M855 (SS109) has legendarily inconsistent performance at range. Most of its performance comes from yaw instability, which primarily occurs at short range.
This discussion requires some background information and a discussion of intended roles as they changed over time. The first place to begin is with the F-86 Sabre. 
This thread will skip over the development side and skip straight to the juicy technical bits of the last Talos variant and shipborne radars. For a highly recommended overview including other variants, check out @VLS_Appreciator 's thread on the topic.