Okay NC, I can understand you wishing to do your own design, as most sparks will do a standard installation (which most time works) whilst some will do a tailored one after chatting with you. But you obviously want ownership of your project, and that's fine.
The problem is that you can't work an HMO and home on the same design principle, so you need to make a decision at some stage before your design takes shape.
But trying to answer your questions on the freezer. Ask yourself how many times you're freezer has gone off, or been turned off by other faults, and that pretty much answers whether it needs it's own circuit. Most freezers defrost by a door getting left open or the freezer dying, so I still wouldn't bother with this one. And a separate circuit for the dryer also makes no sense as it achieves nothing - as I've said before, just use a switched spur off of the kitchen ring.
And as other have said, single circuit for the external sockets and lights will work fine, but it will partially depend on the layout of the house; however, as your external sockets will be 13amp, and your external lighting circuits 5 amp, you'll need to change down the cable size with a fused switch spur at some point. If you think on the principle of how do you isolate a circuit to do work on it or it's components, then this will give you a better idea of how to lay out your circuits.
But you're current design only works for a home, and not an HMO. If you were designing for an HMO, then your freezer would still be on the kitchen circuit, but isolated from the rcd of the ring circuits so that a tenant with a faulty kettle, isn't going to bugger the kitchen etc up.
