One thing I have learned over the years is what works for one, might or might now work else where. I am less concerned with my camera body, which I expect to replace every few years, than I am a lens (which most of them would be about a grand a piece to replace) which I hope to use the rest of my career. I have mine packed in a small hard aluminum case line with foam (egg crate would be better)and they are just small enough to fit in panniers on the back. Now the pannier isn't a shock absorber, but it also isn't transferring the entire impact to every bump in the road to the equipment either.
A tripod won't work that way, though I have to admit I should use a tripod far more than I do. I'd settle for a mono pod but even that would be tough on the racks I have. Id love to have a way to have at least 1 light stand and umbrella (two would be better) so I could take a couple of the old potato masher flashes I have and effectively have a portable studio on a bike. Umbrellas are not heavy but they are bulky. Same with light stands.
The cattrike is a great ride. My Sunray isn't nearly as nice and has two different issues. First is the steering is ahead of my feet so it makes the turning radius of my Sunray much bigger than the cattrike even without the trailer. With the trailer, particularly in traffic it could become unmanageable.
Yea I probably could buy a trailer that would do the same thing and spend about the same, but honestly this time I'm going to build regardless. Its sort of like the guy that buys the vintage bike and spends more restoring it not including the time to do it, than its worth and more than what he could take down to a local bike shop and buy a new bike. Why do they do it? They can afford it and want to.
Yet one thing about gear I learned when hiking years ago. If its going to be that big of an issue to carry, maybe I ought to rethink whether or not I really need it in the first place.