The idea behind the (paper) word backup is that people are generally good in protecting their physical assets but quite bad when it comes to protecting their digital assets. Surely you can find a safe place for your backup (grandma's attic, deposit box in the bank, etc.). Also there is a passphrase I describe in my Q&A post above which renders this backup basically useless if attacker does not know the correct passphrase.
I guess that is reasonable.
Not true, the power is not wasted but used to make the whole "thing work". You use power to verify the transactions and provide so called proof-of-work. Your claim is no different from claiming "VISA/Mastercard waste power in their datacenters for no good reason".
Right now, bitcoin is using more energy than Lithuana. Estimates say, that it will use more than Denmark by 2020. And Denmark actually provides cookies and slightly overrated beers, and Lego. Bitcoin is pretty much just a bunch of useless bits (in the grand scheme of things). That energy can be put into use, instead of providing a untraceable platform to pay for drugs and sex slaves.
And there is the side effects. It is impossible to buy mid-tier graphic cards, because they are just bought for etherium mining. ROI is like a few months, and people buy dozens a time just to make money with it. Because they have access to cheap electricity, I need to pay twice as much for a RX480 for example.
There are second layer solutions coming ... so the energy used to perform a transaction will go down.
Than is much needed, because right now, its not economical, nor sustainable.
I understand, that you have a product, and you want to earn money with it. Its fine, good luck. I mean it.
I am not happy about the grand scheme of things that are happening with cryptocurrencies. It was never supposed to work like that.