His design isn't quite what I'd go for, and I think your overview is pretty close.
I've wanted an excuse to get a biscuit jointer thing for ages, which I might use in preference to tongue-and-groove for everything.
Agreed on the seasoned wood, you'd be surprised at the lack of sawmills in SE23 though, sadly.
The chap in the link considered the mortice and tenon situation and decided on floating tenons, which if I understand things correctly is basically a big biscuit joint.
By all means, buy a biscuit joiner if you want one. But you could also make a custom base plate for the router. A wide flat plate with two parallel batons that straddle the edge of the timber you want to cut pockets/mortices into. I've seen a lot of people do this for cutting out lock recesses etc.
This chap used a hand-held router (and warns about how it likes to tip over mid-cut).
His design isn't quite what I'd go for, and I think your overview is pretty close.
I've wanted an excuse to get a biscuit jointer thing for ages, which I might use in preference to tongue-and-groove for everything.
Agreed on the seasoned wood, you'd be surprised at the lack of sawmills in SE23 though, sadly.
The chap in the link considered the mortice and tenon situation and decided on floating tenons, which if I understand things correctly is basically a big biscuit joint.