This seems to be telling you to make an actual small swale up-slope of your mound so that your mound is not seriously taking water against it... at all. That's a really good idea.
1. slope the lanes slightly down toward the uphill side to direct the water away from the berm in ordinary rain events
You have to have a clear understanding of what this means. True swale works and spillways are going to save your project, no matter what other choices you make. You have to provide multiple gaps in your mounds across each contour of your slope to allow heavy rain events to fill your swale and then pass to the next swale down slope.
2. provide spillways armored with a rock apron for extraordinary events
Yes, this makes perfect permacultural sense, but a traditional hugulkultur does this without the potential hazards, if it's built off contour. Your winter moisture will be preserved within the mounds and a lens of water will be extended in all directions but particularly downhill from the mound, regardless of whether you have it on contour or not. Yes, you will trap more water if you do it on the contour, but it may not be quite how you imagine it, if you don't design it right. For instance, my own raised beds are great because I can plant my garden right away after the snow melts when others in my area are waiting to get into their gardens because the garden is too wet in the spring. This might be the case for the area near your hugul swales... too wet to really work on or do things in the early spring. If you build real swales and proper spillways, then you should alleviate many of the problems.
So it makes sense to try to trap enough rainfall to keep the ground moist all year. So I have taken to heart to slow, spread, sink, etc as all good permies will do.
Good call. My advice: Walk the site, and envision various ideas that you have as already existing. Walk the path of the water as you envision it to flow on the slope, through the various structures that you are conceiving and through the living things, as it proceeds downhill, and downwards in the Earth, and back into the sky. Just FYI: Any slope greater than 25 % is too steep to build swales and is best forested for natural/indigenous regeneration, rather than production/economics.
1) there are ways to do this without collecting a lot of surface water in the slope and 2) I might as well wait until early January when I will be in residence before detailing my system, so I can measure particular slopes, etc.