When you are running backward and hits are registering 10 feet away .. that feels right to you?

I don't recall any mobs running backwards and swinging at me either. I've noticed that it's easier to hit retreating than advancing but have never heard an explanation of it before, thank you.

It was explained to me that you do it with a reach weapon- greataxe, greatclub, maul, etc. because you're swinging far enough from your body that they would be running into it trying to melee with you. As for whether it is an exploit or not, there have been several times that I've tried to chase a kobold down a hallway and he just keeps jumping out of my reach, but somehow still hitting me. Usually they just jump. More recently, I've been trying to play smarter, and not chase jumping kobolds down un-scouted hallways though

I have yet to run backwards and hit a mob "10 feet" away.I move quite a bit when I fight,and when I solo,mostly backward.As I have said,it hasn't been that far away.What commonly happens is that when my weapon has a longer reach(like great sword or axe)vs a shorter weapon,I hit first,but do not pummel the mob from "10 feeet away".So yes,it feels right to me that a longer weapon has a greater range,let alone 'keen' weapons.Funny thing is,it works when I advance too.Huh,how bout that.

I just tested it again, and I can kit a kobold running backwards while its chasing me while it appears nearly 3 body lengths away on the screen. My greatsword is definitely not the length of 3 Warforged. Weapon size obviously plays a factor but cannot explain that. Can you?

The only time I've ever seen this dubious tactic was Flave. I doubt Rosco could have pulled it off with his old computer. His new one makes it possible but I doubt he'll care for it or even try something that cheesy. Flave is gone. Hopefully this expoit is too. If folks are using it, they should stop. It's one thing to take a few swings as you pull back to the group or something, but deliberate exploit of a mechanic like this is not MV. I've not tried it, but I'm guessing the number of mobs you could do it with is limited.

Again, bottom line; you want cheese, go elsewhere.

Tried it on numerous occasions tonight.I noticed foreshorting gave the appearence of greater distance,yet when I checked positions vs the map,the greatest distance I could get was about 5-6 feet,assuming 10 foot squares.It is certainly possible to strike that far in "real life" with a greatax,greatsword or spear.It might be your guys comps can do it,but mine can't.

One of the things that has changed for me is the 'lack of lag'.I used to have to anticipate fights,especially ones with lots of pyrotechnics.I tried to compensate for the lag by making WAGS and moving and striking even tho I couldn't see action on the screen.If this indeed a lag generated "exploit" I haven't seen it in the last month,even when I tried.

Tried this challenge out and made it up to chapter 4 hard, where i died mostly due to sloppy play, at 27089 xp. Got hit by a scorching ray from a shaman I didn't see while fighting the Interrogator. My build was:
Warforged Cleric
Str 18, Dex 12, Con 12, Int 8, Wis 12, Cha 6
Feat : Adamantine Body

I had some trouble with Chapter 1 because of no access to a decent weapon, however once it was completed, I got the enhancements for Greatsword proficiency and Damage Reduction. Bought a couple of regular greatswords from the harbour smithy and 400 throwing daggers and it was smooth sailing all the way.
No decent loot whatsoever, Goldscuttle gave me a Kama of lesser reptilian bane and a bunch of ammunition. The best available reward from Waterworks completion was a +2 Heavy Crossbow which wasn't that much more effective than throwing daggers for a 18 Str character.

I might try this out again someday... enough Waterworks for a while.