Everything Madonna does in terms of dance is rooted in her Modern Dance training, combined with whatever she's interested in at the time - voguing, hip-hop, yoga, etc.
Britney just kinda did the whole Janet Jackson thing - but what she did, she did very well at the time.
Britney could never pull of 5:15 to 5:45, even when she was at her peak.
Sis, you can't be serious. Brit has done many routines that were faster and more complex than this. Primeney would have learned and mastered that thing you just posted in under 15 minutes.
I think the Open Your Arms live perf is one that Britney would struggle to mater, but she would end up doing them. There is not a single routine Madge has done that Britney couldn't do and vice verse, it's the technicalities of their dancing skills that make them subjectively better than the other
Paula Abdul is better than both (in terms of choreography) and Jlo is better in terms of diversity.
Madonna is the better dancer obviously, some of her moves are too complex for Brit but I can see Madge doing all of Brit's moves
I thought those two would go without saying. It's a given.
And no. We never saw Britney's full potential as a dancer in her prime. She mastered the fundamentals like ballet or jazz even at a young age. The fact that she was also a gymnast puts her leagues beyond what you non dancers are capable of comprehending.
Madonna implanted a lot of traditional and classic styles through her trajectory, as well as her own.
Britney never really showed us what she was capable of doing. She mostly stuck to Janet's choreo style and added some flips here and there but it doesn't mean that's all she can do.
Honestly, I'm even undecided here. 
