I assume you are UK based since you use metric dimensions.
My wildlife pond is plants, planted loose, in soil, straight over the liner with the exception of where there are large folds, there I put a flat layer of plastic over the liner so that the roots cant get into the fold. Personally I am very pleased with the result.
What Koi-lo says about the roots growing all together is true but, with the exception of reeds (possibly norfolk reed) and Typha latifolia, reedmace or cattails (frequently incorrectly called bull rush) that doesnt bother me, I should have potted the reeds and cattails in solid containers.
Re making it animal friendly, I would suggest that you ramp the soil on the shelf so that it breaks the surface within an inch or so of the edge of the pond, if you dont want it breaking the surface then bring it to within 1/2" or slightly less of the surface. My shallow shelf is about 2" to the liner and the soil breaks the surface, I think it would have been deeper to the liner with a suitably thicker layer of soil.
If you are UK and you want fish I would stock the pond with either minnows or sticklebacks, my stickle backs jumped into a suitable container whilst I was walking in a feeder stream for a local resevoir.

DO NOT add the plant Tillaea recurva, Crassula helmsii, australian stone crop, http://www.arghamvillage.co.uk/produ...ails/9211.html its chuffing invasive and can smother more desirable plants

My pond is not filtered but there is a pump driving a small stream. I do not feed the fish in the pond apart from once in a blue moon with any mosquito larvae I find elsewhere in the garden.
If you do like wise then until the higher plants become established expect the pond to be thick with blanket weed but since the end of my first season I have not had any blanket weed. I added the floater azolla during the first summer and that thrived but again since the higher plants became established the azolla barely ticks over and I would doubt it I have more than 6" square of it. If you use azolla during your first season and harvest any of it COMPOST the crop do NOT throw it out. I would suggest you harvest it once you see it start to turn red, it can die off and sink rather quickly and in another pond which was totally covered by a thick layer of it the decaying material on the bottom of the pond could be smelt in the air around the pond and would probably kill any animal life in there.

My pond is surrounded by turf, small amphibians, in my case froglets, can stick to hot dry concrete and probably rocks, they will then dehydrate and die. The only way they can be released with out skinning them is to soak the concrete with water.

How are you thinking of 'land scaping' around your pond?
What plants are you thinking of? Lilies my be inadvisable depending on how wild you want your pond to be, they may not like winter and early sppring competition for light whilst 'running' on over wintering pads. I suggest you stick largely to native plants.