Are fees necessary for clam? If staking is same and not ending over the time ?
I guess part of the point of fees is as a spam-prevention mechanism.
If it cost nothing to make thousands of transactions just sending coins to yourself then that's an easy way for an attacker to bloat the blockchain.
Also, without fees there's no incentive (other than fuzzy "help the coin" incentives) for stakers to include any transactions in their blocks. They would get paid the same whether they stake empty or full blocks, and full blocks take longer to propagate and so stand more chance of being orphaned.
This can change though.
I imagine the block reward will be reduced in the next 2 years or so.
Why's that?
One of the things that sold me on CLAM was the linear distribution curve
I wouldn't get to nervous about this. That's one Man's opinion, note the use of the word "imagine".
To keep a POS coin network alive you need to have lot's of nodes moving the block chain along. The people running the nodes need to be compensated for there time and resources. At present, the transaction fees are increasing, but don't amount to much. In the last 6 stakes I've made .0014 from the fees. hardly enough incentive to keep a node running.
The way I see it, staking your coins is simply a way of "keeping up with inflation". The total money-supply goes up 3% per year, but your CLAM balance also goes up 3% per year and so your percentage of the market cap stays constant - in that sense PoS money-supply is the "good" kind of inflation. It doesn't erode people's savings.
It doesn't really matter what that "3%" figure is, so long as it's big enough to encourage people not to opt out of staking and small enough that the money supply doesn't get too big.
There will always be some people who don't stake their coins, and so by staking your share of the market cap will be going up while their share goes down. That's how it should be, and results in more people supporting the network by staking their coins.
, good luck 
