Looks good, it's just unclear why you picked Bitcoin hashrate which is generated by ASICs working a million times faster than a computer.
I picked it in a search for a maximum possible hash rate owned by an attacker.
In fact here I assume the biggest ASICs farm is like a billion times faster than a computer. You are correct that ASICs farms wouldn't exist without the Bitcoin economic model. I.e. the ratio E/J wouldn't have grown to billions. But even if it was smaller, you still need a minimal number of transactions per second with the magnitude of E/J.
Anyways, good luck!
PS:
Iota is like a russian car: if it stop, it cannot start, but once it start, it cannot be stopped 