Let's see, I think I see a few things that need correcting, and then plenty of space to make some personal input on issues. Here we go then...
>Vikings issue> I certainly wouldn't recommend "Indostrous" for the poor ol' Vikings, as they were by far more concerned with trade and/or plunder than they were with building a strong infrastructure. Expansionist I don't think would be quite it either, seeing as how most of the Viking colonies and holdings were acquired by brute force rather than actual civilized settling of the lands. Commercial - Militaristic would be my call for it, but I'm not saying it's end be-all end-all solution to it. As for a UU for them I would say the Longboat or possibly some infantry unit capable of amphibious assaults, seeing as how that was basicly what the Viking raiders were doing most of the time.

As for a leader Harald the Red hardly had much impact on the overall "Civilization" of the Vikings, but still, he's fairly famous. Though I do think ol' Harald did more as a "leader of men", as it were.
>Blackdragon> The Mongols as earlier noted I agree do deserve a place among the glorious Civ's of Civ 3. South American might indeed deserve another representative, but I don't think more than one would be needed. To most people's eyes there were little difference between the Inca and the Maya, even if such is not actually true. On the other hand, seeing it Civ-wise, the Portugese hardly deserve a place among the other. If anything a Spanish Civilization would be considered to incorporate Portugal, much as Russia is thought to include Ukraine, Belorussia and the Baltic states, Zululand most of mid to south Africa etc etc.
And the Tibetans, even though once more important than now, do by no means qualify in the long run. They simply never were THAT important.
>Assyria> Both the Assyrians and Hittites are already in the game good people. They're considered a part of the Babylonian Civilization. And frankly, if Sid Meier were to incorporate every little would-be Civ from all over time and space it would be too full of them. I agree the Assyrians weren't actually Babylonian, but there was, come to the core of it, quite few actual differences between their culture and the Babylonian one.
>The Ripper> Turks have been discussed over and over before, and a lot of people feel they've been unfairly left out. Militaristic and Religious would indeed hit the spot when describe the ( Ottoman ) Turks, but I myself would prefer to include the Janissary as their Unique Unit more so than their cannons. The images of HUGE Turkish cannons pounding on city walls were mostly romantic fiction, and the large bombards the Turks used were by no means unique, only found in unproportionally large numbers in the Turkish army. The Janissary on the other hand actually did use a concept never before used in fully in military history, and thus was somewhat unique. I wouldn't know exactly what to make the Janissary in-game as it evolved with the Turkish empire, but most likely an upgraded version of either the Musketman or the Swordsman, depending on which era you pick him from. Most likely a Musketman.
Mamelukes on the other would not fit the Arabs, as the Mamelukes were an Egyption warrior-slave caste utilized first by the Fatimid rulers in Egypt. Perhaps the description you gave them stats-wise was fair, but hardly good for a UU for an Arab Civ. More likely some Fanatic unit or something would represent the post-Mohammed period of violent expansion, say a swordsman with +1 attack or move, or some such.
As for the conceived Spanish UU they are overall more known for their Conquistadors than the Toledo weapons, even if the latter are quite well known as well. But overall the Toledo smithing never had any great impact on warfare, to be certain, it was superior to most other European ( if not middle-eastern ) swordsmithing ( most of all ), but on the large scale it did little for an army. It was such a small superiority as to be negligable when considering huge armies clashing together.
>Byzama> Patriotism in all honor ( something which I lack ) but in truth the Finnish hardly deserve a place as a Civ of their own. Now I have nothing but good thoughts on Finland ( having family from there and whatnot ) but seeing as how they've not even a century on their neck as a "real" ( free, rather ) country it would make them even younger than the Americans, and they are already borderline. And even though their resistance of the Soviet union was impressive, one well-fought conflict does not shape a Civilization. Or as Yoda would put it "war does not make one great".
And yes indeed, most of the Finnish resistance troops were in fact skitroopers, this i can account for personally, seeing as how my grandfather fought as one of them. Old man managed to get mortar-shrapnel through his shoulder too.

Anyways, ergo whilst the Finnish did mount a very impressive defense for such a small country versus one such big, they didn't quite *beat* the Soviet. The Soviet could have ( and did on occasion I beliee ) occupied any Finnish city they wanted, what they were unable to do was to wipe out the resistance mounted by the skiing soldiers. Scared? No. Annoyed? Certainly. Hamped by? Indeed.
And yes, Sweden did nothing but cower down in World War 2. But I can't say I blame them. Even though it was way beyond cowardly to allow the Germans to pass through Sweden to Norway they had little to gain by fighting. Like most other Scandinavian countries they would have been trampled down utterly by the huge world powers of the time, and seeing as how Sweden came out none the worse for wear after the war I surmise it was not such a bad decision overall.
Well people, rock on! If you survived reading my arguments all the way down to here you deserve it. :crazyeyes