I wouldn't expect anything as tender as Runaway from Jay and Kanye together but I'd say Why I Love You does 'grandiose' well. And it's funny you should mention Monster as an example of going hard given that Jay sleep walks through his verse and proves himself to be far more agile and cutting on Watch The Throne, particularly tracks like That's My Bitch and the incredible Who Gon Stop Me. I don't know if I'd describe All The Lights as inviting (as amazing as it is), but New Day and Murder to Excellence have a similar narrative feel, while Made In America is far warmer that anything I would have expected from this particular collaboration.
As for the tracks you singled out; Niggas In Parris is just so knowingly audacious that I can't help but get caught up in its madness; Otis has some excellent one-liners but it does tread the line between clever and irritating as far as the sample goes; Lift Off is lacking in actual rap but features a chorus better than anything Beyoncé herself has produced since Sweet Dreams; and No Church In The Wild sees everyone involved playing a blinder, particularly The Dream's verse.
It's not as sprawling or surprising as Beautiful Dark Twisted Fantasy (how many albums are?), but Watch The Throne does take some its cues from that album in terms of variety and scale but in a more streamlined fashion.