Brambles are fine in the compost heap - they don't root themselves from the branches, but you wouldn't want to put the roots on the heap. The main problem with bramble is it's tough and woody so will take ages to rot down (mine have though, in 2 years: I chopped them into about four inch pieces).

The top growth of nettles is perfect on the heap, you don't need to soak it first.
The roots of perennials can be baked in the sun until brown and crispy, and then added to the heap/Dalek.

Dalek can be sited on concrete - try and import some tiger worms from someone else's heap if poss to speed up your decomposition.

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