3. K-37M is for aircrafts like AWACS, I dont think AWACS are classified as high-speed targets if I read that paragraph from Tass correctly.
The R-37M is designed to engage targets pulling up to 8g, so it is clearly designed to intercept a much wider range of targets than just large AWACS or strategic bomber or inflight refuelling or JSTARS type platforms.
Being ARH it can engage very low flying targets too including strike aircraft like the F-111 or F-15E or pretty much any modern fighter.
Ramjets offering 50%+ more range than current propulsion methods is nothing out of the ordinary.
Soviet medium range SAMs went from the rocket ramjet powered SA-6 to the rocket powered SA-11 and SA-17 and SA-25 because solid rocket fuel developed faster than ramjet design did, but with scramjets the top speed of missiles is massively increased without using a lot more fuel so where before the Kh-31 was managing mach 3 a scramjet model would triple that speed potentially at a similar fuel burn rate... triple its speed and you massively increase range performance.
Hermes is at 100km because the 1st stage offered it 80kms and the sustainer 2nd stage offered it 20kms. Since the sustainer stage will be replaced with a ramjet https://en.topwar.ru/176806-kakim-budet-giperzvukovoj-raketnyj-kompleks-klevok-d2.html 40 seconds going 7000km/hr would mean a 80+77.77= 157.77km range. Keep in mind the goal was also to bump the klevok-d2 with a warhead that weighs twice as much than using that weight for fuel. K-77M is at 193kms and more than likely a ramjet version of it will use the same warhead weight.
AFAIK there was no sustainer terminal phase... the missile just was a glider that fell on the target with terminal guidance for a direct hit.
The purpose of a ramjet sustainer motor was not to increase range, though that is an added benefit, the purpose of the sustainer is to allow powered flight so it can manouver and evade enemy air defence on its way in to hit the target making a target hit vastly more likely than with a munition that glided in like a guided bomb.
TOR and Pantsir are designed to hit gliding weapons so the new HERMES would allow your precision attacks to get through and hit the target more often... in the Ukraine such a missile would be used first to hit systems defending targets like TOR or IRS-T or whatever western system they have... once they are defeated then cheaper simpler weapons and drones can take out everything else.
For priority targets like artillery vehicles or radar or drone control stations or EW stations then Hermes will be very useful.
What I think would be also useful is those new Pantsir missiles with four mini missiles per original launch tube... at the moment they are four missiles with four solid rocket boosters, but imagine a version of Hermes (which is based on the same missile) that has one big solid rocket booster but you mount the four mini missiles for anti drone use... the ballistic rocket launches them in the direction of the threat and then the four missiles can separate and each go after a separate target... each missile could have an 6kg warhead each with a shaped charge and shrapnel lining to hit armour from above because the original missile has a 30kg warhead so four with 6kgs would be 24kgs in total... so the 6 missiles on a HERMES truck might be carrying 24 individual missiles to hit targets 50-100km away.