Immortal strategies are perfectly valid on noble-monarch. There might be some weak strategies that work on noble, but not on immortal, but it's not like you are forced into a style, like in Vanilla Deity, where you needed to be super-aggressive. AIs don't get big bonuses any more (and immortal is just plain easier than it used to be), so any style will work. It's not like Sis is exactly a builder anyway.
Oh, I'm a builder at heart. I war to build, as a former regular of the ALCs once said. I'd be quite happy to sit back and build wonders all game long if the AI civs didn't get in the way...
As for immortal versus emperor... First off, I have to say that I have not found the jump from Monarch to Emperor to be nearly as challenging as previous jumps (Noble to Prince, Prince to Monarch) were. Maybe that's just because I've been playing the game so long now and have been getting such great advice in these threads.

But I almost feel like there's something else at play, like maybe the AI's advantages from Monarch to Emperor aren't that substantial, or perhaps the patches have nerfed them and/or the AI. I don't know. I just know that I've only played 4 ALC games on Emperor and I'm already feeling like moving up a level, whereas it took 11 games for me to really feel ready to make the jump to Emperor.
It's true that all the strategies I use on Emperor (and would use on Immortal) are valid at the lower levels. However, what's different are the strategies I
don't use. At each higher level, I find you have to give some things up. I used to always build the Oracle on Prince, for example, but started giving it up in Monarch. Now I almost never go after it unless I (a) start with Mysticism and (b) have marble available. That is the price the ALCs pay by going up difficulty levels: additional in-game goals that are viable at the lower levels are abandoned simply because the higher levels are about
focus. This last game is a perfect example: I didn't build a single world wonder. That proves that the wonders are not required to win, but then again, they're kind of fun, aren't they? I wouldn't want every ALC from this point on to be a repeat of this one. So, moving up is not a decision I take lightly, for many reasons.
Leaders don't have to be your vassal for you to direct them in war you know. You can ask anybody to attack whichever city you want as long as their in a war as an ally with you.
True, but what I'm beginning to analyze is how successful (or not) those requests are. Does the request carry any more weight for a vassal versus an ally, for example? And how much of a factor is distance?
that screenshot showing your victory conditions is from 1810. I see from the log that Hamm capitulated in 1812, but in the interim you reached the land and population threshold first, so it was a domination. But yes otherwise if you make everyone a vassal it's a conquest. here is your screenshot from the last save showing domination
Thanks for clearing that up!