I can find no clarity on how much funds are being raised in total. I've also read reports on Telegram increasing their goals in line with public interest. There even seems to have been no consistency in pricing offered to investors during the private sale (www.theverge.com/201...
Achieving what Ethereum could not? This was a recently abandoned proposal Vitalik Buterin.
Regarding the MTProto's "Security by obscurity". Some would argue that this is desirable for a messaging platform; certainly not for a blockchain.
So Durov's research consisted of harvesting the most ambitious ideas from a variety of projects?
Neither from this document or the technical paper am I given even a slight intuition as to how it is proposed that these challenges will be solved.