Hopeling

I'm not sure if you're aware of this particular factoid and it's not a good hour of the morning for me to check the math myself for this particular build, but there's a certain subset of Broadsword builds for which the best ST attack chain is Headsplitter-Hack-Disembowel-Hack even though they don't have the recharge to run it gapless. It's better to spend .3 seconds or whatever after Disembowel doing zero damage than to spend 2.244 seconds using Slice for low damage.

BS/Inv is a solid combo. I ran one as my main for 18 issues before a couple other characters became my favorites. But I never found a way to use it to set solo speed records. If your goal is to compete with 7 other people for speed going through spawns, like you mentioned in your first post, an AoE from an ancillary pool really helps, redraw notwithstanding. Fire Ball (or Ball Lightning if you prefer) does similar damage to Whirling Sword, except it animates faster (even if you count the subsequent redraw as part of its animation time) and hits a lot more guys by virtue of its larger radius. If you don't want an ancillary AoE for concept reasons, Body Mastery is a fine pool as well, it's the one I used. It would be difficult to get sustainable endurance for soloing AVs without it. But it's not the best choice for mowing down spawns.
If you want to spend twice as much, you could take advantage of dual builds and have one for each purpose.

Nor I usually (except a brief period on my Bane after I got Surveillance and thought it was really cool), but a bizarrely large fraction of my most-played characters deal primarily lethal damage, and the next-most-often-played character deals smashing damage, so the difference is quite noticeable to me.

There's no contradiction here. The thing you correctly cite as his core argument leads with "While the structure of Katana and Broadsword are identical...". There is NO meaningful mechanical difference except the DPA. That's why comparing just their DPA is meaningful, because they are otherwise extremely similar. It's comparing apples to apples.

No, there are quite a lot of enemies with lethal resist, but less/no smashing resist. Malta Titans, for example, have 50% lethal resist but only 30% smashing according to Paragonwiki. Rikti Drones seem to actually be vulnerable to smashing, but not lethal (never taken a power analyzer to this one but I always get unusually large hits on them with my SS/ brute), and Carnies are vulnerable to lethal but not smashing. Robots in general seem to resist lethal far more heavily than smashing.

Edit: If the NPC is getting resistance from a version of a player power, like Temp Invulnerability, then it will give equal parts smashing and lethal resist of course, but their base resistances are quite another matter.

Well, like you said, it took us 4.5 billion years to get here. But the universe is something like 13 billion years old, so there's plenty of time for other species to have a head start. And, again like you said, our technological advancement in the last 100 years has been very rapid. By all indications, that rate is going to continue or increase. So even a small (on a geologic scale) head start would mean that another species could be far ahead of us now, even if they have no other advantage.

That doesn't mean EVERY alien species in the universe would necessarily be more advanced than us, but some of them would be. And if we encounter any aliens, it would be the more advanced ones, since the less advanced ones can't get to us, and we certainly can't get to them. Yet.

IO procs have a flat chance to fire. If you use the power more often, the proc goes off more often. This is why procs are great in buzzsaw chains, and lackluster in nukes. Katana powers are faster, so it uses more powers than Broadsword in the same amount of time, so the procs go off more often.
Indeed. Every now and again there are threads brainstorming ideas for those other older sets, too. Right now you happen to be in the Broadsword one. Different sets having different performance is great; I wouldn't like my various melee characters nearly as much if they all played the same. Different sets having strictly superior/inferior performance is another matter.

True, but that's not really a good or bad thing, it's just a thing. With a normal 95% hit chance, Broadsword has a 1/20 chance to do zero damage with its one attack, while Katana only has a 1/400 chance to do zero damage with its two attacks together.
The procs alone don't make it a stronger set, but it's yet another point in Katana's favor.
Yes, but "faster" does not have to also include "just plain better".

Comparing the DPA of every melee set is not nearly as useful a comparison because those sets do vastly different things. Spines or Electric Melee have worse DPA, but they also have more AoE than Broadsword, so you have to account for more things to make a comparison. Katana is the most direct comparison, and it's a comparison where Broadsword comes out behind in every meaningful way. You can compare it to all of the other sets and account for all of the differences, and Broadsword again comes out behind.
But I DO like the set. And I DO play it. I have not one, but two level 50 Broadsword Scrappers. One of them is my oldest character, and was the first character with which I did basically everything up through I18. The other was the first character I took to the iTrials. I would just like to play them without that nagging feeling of "I could be better in every way if I rerolled with Katana or War Mace."

On the last page you said:
...but that was already the tone of this thread from the very first post. I haven't seen anyone say Broadsword is a bad set, just that it should have something special to call its own to make it not just "Katana except inferior". Lord Rahvin said it nicely:

Right, but my greater point was that Titan Weapons isn't even a slow set. It's overall a pretty fast set, you use 1 attack that's moderately slow (roughly Head Splitter speed), followed by 3-4 attacks that are quite fast (1-1.3 seconds before Arcanatime). So your total number of attacks per minute or whatever you want to measure by is on the high end, and Fury generation will be strong.

I don't see why it would need to be normalized, when TW attacks are not even the slowest powers out there, and 4 out of every 5 attacks used can be blazing fast.