[Ethereum] Where does the consumed ether/gas go

There are several different options for a private/consortium chain setup:

1. Use a custom genesis block to set the difficulty level for mining to make it less intensive. Only turn mining on for some of the nodes that are participating in the network. In addition, you can pre-fund specific accounts
2. Use something like Parity's Proof of Authority chain to configure who the validators for the chain will be
3. Create a permissioned ledger using something like HydraChain that does not require Proof of Work and provides faster block generation in addition to full customization of gas, transaction fees, etc...

These approaches should address some of your questions. But keep in mind gas plays an important role when it comes to the execution of contracts. One of the main motivations behind gas is to prevent the Halting problem. Which means without gas, it would be possible to create a contract that could potentially run forever opening up the possibility of various attacks such as Denial Of Service.

I agree with gatb27 about using Browser Solidity to get a feel for it.

Here's a little toy that does approximately what you described. Paste the code, click create, and then set a name.

setName() expects you to provide a quoted address and hex string like this (copy/paste should work):

"0x35ef07393b57464e93deb59175ff72e6499450cf","0x1"

You can get the set values back with the other function and just the address.

pragma solidity ^0.4.6;

contract PlayWithGas {

  mapping(address => bytes32) names;

  function setName(address userAddress, bytes32 name) returns(bool success) {
    names[userAddress] = name;
    return true;
  }

  function getName(address userAddress) returns(bytes32 name) {
    return names[userAddress];
  }
}