Punky wood is perfect for hugel mounds, it is a sponge when it comes to water retention.
The species you mention are not going to affect pH greatly, they are already well on the way to fully decomposed.
If you use it this way, you will use less water to keep your vegetables and other crops well watered.
You do not have to build mounds to use the hugel method, you can dig down, lay in the punky wood then put the soil back on top.
Plant what you want and be happy, your watering needs just went down.
As for using it for mulch, it will work very well.
The other items you mention; horse manure, leaves, wood ash, lawn clippings, seaweed, eelgrass, fish waste, lobster and crab shells. Wow, what a
compost you can make with all those ingredients!