Yes, I understand and share your concerns. But I'm afraid there's probably not much that can be done about it. Also, slowly buying 100k BTC is very well within the reach of many people or investors right now, so this is not something a restart of the blockchain or a switch to another coin would solve.
Well, actually it does, obtaining that many LTC is not really possible without causing a immediate bubble since it is already more popular than Bitcoin was at the beginning.
What do you think is the kind of power they are going after?
For all we know, many of the early mined coins which did not get moved might as well be lost - they weren't worth anything at all and the software was buggy.
Also, the BTC-rich probably don't have an incentive to crash the market by selling all at once. If they would do it slowly or use the BTC to buy real-world stuff then I don't see a big problem - the BTC would just get re-distributed over time.
If that were the case the decline from USD 30 would have been way steeper with the total number of bitcoins traded being much higher. If that were the case we would already be at the Slope of Enlightenment and possible at higher prices with a more even distribution of wealth.
In the current situation the market has to "force" the bit-rich out of their holdings by declining even further to a point where the success of bitcoin becomes uncertain.
As for the economic power I think some people are after:
Think of a scenario where one Bitcoin is worth the equivalent of one ounce to one kg of gold.
Lets say there is a market for 3D printed goods as a major part of the economy. Such an individual could just buy out all producers of PLA plastic strands eventually creating a monopoly.
Even worse it could be used for economic blackmail like we have seen with recent 'banker bailouts' in the fiat economy or even create something like a 'new royalty'.
As for the hypothesis of lost coins: I don't really believe that. Especially people who went after a significant amount of bitcoins knew what they were doing, I don't think more than 1% of currently issued bitcoins are lost.