TerraHash 1.6TH don't work.
they would work; if the owner was to set up, a private pool.
you will find, that this may happen at your launch, you won't be able to avoid it, i'm afraid - and your coin will be forked before you can say 'confirmed block'. Anything that you can solo mine to a wallet, you can set up a pool for.
here's a hypothesis for you;
big garage full of 1TH/s dragon miners and a geek with far too much time on his hands; installs a private pool on DO and compiles the wallet on launch. 20 minutes later, he hooks up his 20 x 1TH/s dragons and plunders your 1seventoshi blocks until he has mined enough to give him a jolly good laugh. Then he switches to failover, for 5 mins, then pushes his rigs back onto your coin, via his private pool.
coin forks to his node;
this is called: The Point of No Return.
I hope that you really have got some protection for all the little miners who intend to be part of this because to me, as I see it, nothing is foolproof and specifying a 1seventoshi block reward, does nothing to stop the above scenario.