The entire DRK instamine cost less than 50 BTC for two weeks after the launch.
I'm talking about amount of coins, which is what matters to the distribution of a coin. If you convert them to BTC then you have a BTC potential distribution issue and also a potential coin distribution issue with whoever you sold them told (or not, it depends).
Don't conflate the two.
Initial distribution would only be a problem in a world where markets do not exist. When the markets take over, distribution is sorted out according to demand.
No it is still a problem when markets aren't liquid or people don't pay attention. You are assuming markets are infinitely liquid and everyone (or most) participate.
If someone starts with 80% of the coins when they aren't worth much, puts them away somewhere and they go up in value, then one day you have someone owning 80% of the coins later when it does matter (and when it is probably even harder to trade in such volume). This may also be an issue in coin markets which can move very fast before anyone even realize what they're worth.
You are mostly talking hypothetically now. It doesn't add anything.
The number one Darkcoin wallet has a significant proportion of the entire coins in circulation. He purchased every single coin on the open market. The huge amount of money that was being transacted has distributed the coins. Quite a few of the top wallets show reasonably recent purchases.
Those that are long-term holders, well a great deal of them are working on the project for free - I suspect many have had to sell coins to pay for living expenses and the like.
As was pointed out, this is all with the backdrop of Satoshi and his pile of coins.