You can understand the api_key as your password that ensures that only you can execute the endpoints. Therefore, "decide what api_key you require..." means that you have to choose a string as

Well not particularily, the Chrome app is just one way of using the wallet. You can also just download the wallet and unpack it locally... This way would still be possible, whatever Google plans for Chrome

1 and 2 are good ideas. perhaps we could organize a crowdfunding campaign on waves to finance the efforts. I'm not sure if 2 is so hard to achieve, there are things like electron that could be used...

Some other things might be pretty important that do not come directly from the financial sector, e.g., Distributed Trusted Timestamping seems to be an interesting approach for intellectual property rights