Re: 8,192-bit keys
Total overkill, as even 2048 bit keys are still fine now and for the next decade. While they won't be fine forever they'll be fine for the useful life of the networking device it will be installed in.
At a certain point even if throwing nation state budgets at it would eventually crack a 2048 bit key in 3-6 months, you don't have to worry about that. What you really have to worry about is all the other stuff unrelated to key size - issues with key management, corner cases that allow MITM, flaws that allow accessing the decrypted data, that sort of thing. That's how you'll get hacked if you use a 2048 bit key, the NSA isn't going to devote a room full of supercomputers for months to crack your key. Using a key that large is just wasted resources.