Worst a 51% attack could do is halt confirmations of all transactions until the hashrate drops. Not really a problem.
that's still a dos attack, and that's still a problem
until the hashrate drops or like within 10 minutes.
I'm not sure I understand, if the hashrate drops significantly, it could take longer than 2 weeks for it to adjust.
blocks would be very slow in the meantime,
it's still a denial of service attack.
is it not?