UPDATE: TAU AND DIORAMA QUERIES

Hello again folks, it has been 4 weeks since my last post and I have done very little. I have based the Tau Firewarriors, Pathfinders and Battlesuits. I have painted 4 drones, I am working through 5 drones, Kroot Shaper and a Battlesuit. All at various stages of completion. I have some one off pics just showing off the basing and a sneak peek at the drones I have completed. I also have some questions for anyone willing to answer them. Here are the pictures:

And now for the questions section of this post:


INTRODUCTION: I am planning to create a Diorama for a local painting competition that is happening next year. My idea is very simple as it is my first attempt at one, I will have a Barbarian (Grenadier Barbarian Cap'n) standing in the middle of the diorama on a mound or small hill. A small burn will flow in front of him and various shrubbery and rocks will surround him.

Q1. What materials should I look into using for the burn, the rocks and the hill?
Q2. Should I mount the diorama on a plinth or leave it as a free standing base?
Q3. Should I leave a 'base space' for the figure to be placed on OR because it is a pre-slotta base should I just make it a diorama and leave him there forever?

Bear in mind I am painting the figure separately and any answers are much appreciated. Answers do not have to be long, if you leave any links to good tutorials I will be very grateful. Bye for now.

P.S. sorry for the length of this post and please look out for my photos from the Flickr pool on GW. My name there will be MCNALIEN. Thanks for reading.