Don't consider that gospel. I think it's correct, but I'm not positive.
You can always demand more than 1, but as I understand it, only the first will count as the one that's part of your vassal agreement. They can refuse the second or third demand without provoking a war. I know it used to work that way, because I've had it happen, but I'm not sure whether that was intentional or if it was a bug that got fixed in the latest patch.
Well, if I ever get the time to play another game instead of Civving vicariously through Sisiutil and aelf, I'll definitely test it out, since vassalizing *can* be fun like you said before.
Regarding the game at hand, I can see why you said the game was far from lost before. That other continent is looking like Oakland to our continent's San Francisco.
Looking towards the future, I agree that war with Ragnar will probably have to happen at some point, whether to deny him a space race vic (through a relatively short campaign to kick his production in the hindquarters) or to give us a domination vic (I also think consolidating our continent would be a key component of that). That war could easily be held off until late in the game, when we've had a chance to consolidate the former Nipponottoman holdings and have been able focus tech research towards closing the military tech gap with Ragnar.
In the meantime, Sisiutil, I'd go ahead and make the switch to Toku as Public Enemy #1. My military advice, for whatever it's worth, would be to move your main force S through Viking territory and strike East to Tokyo and Osaka. From there, keep going eastwards to Kagoshima (by way of Kyoto) if at all possible. Rip out his heart as fast as possible, don't worry too much about Mehmed at first. You've got solid defenses near him and could always use a reinforcement elephant or two as a temporary counterattacker if he gets frisky and starts pillaging. Edrine's cultural push won't be strong enough to worry about yet. Think of Mehmed as a terrorist cell - he can cause a bit of a disruption but doesn't have the muscle to be a bigger threat.
The focus of the war should be to cut out the heart of Toku's production first, so that even if he does manage to suddenly spring cavalry on you, it'll only be a minimal number. Remember your WW2 history

- Hitler may have had the Messerschmidt Me-262 Jets by war's end, but his production capacity was so wrecked the few he was able to produce weren't able to make a big enough dent to affect the outcome. If there's even a risk of being outclassed technologically, you have to make sure that he can't put that superiority to use. If you can secure the 4 cities in his production heartland, you can turn north or use future reinforcements to take out Mehmed afterwards without too many problems. At that point Toku will either be asking for capitulation (not likely knowing him) or you'll be in mop-up mode.
Good luck, soldier! Now...MOVE OUT!
