Thanks, I will give minrelaytxfee=0.0002 a try. Not really happy with the solution, but it seems there is nothing else I can do for now.
Can't you enable swap? With swap enabled Bitcoin Core doesn't seem to have any significant problem dealing with the current flood. The overall server response time does increase but nothing crashes, although I haven't tried running 32-bit versions on the mainnet in a while.
Nope, no swap or hoster gets mad. Its pretty stable now, but the attack stopped anyway[1]. I guess I will have to wait for the next wave. Fow now the log script I wrote should give me more insight if it should crash again. I should probably considering an upgrade, disk space is low anyway.
[1]
http://statoshi.info/dashboard/db/transactions