Why even download the wallet without the mainnet release? I would expect that many were waiting for that. I mean, thats what I'm waiting for.
My question is - Will there be masternodes? or a way to stake my investment?
Yes, Masternodes will be available. The reward structure are as followed:
Masternodes (PoW): 25% of total block reward.
Supernodes (PoS/PBFT-like consensus) 75% of total block reward.
Check out the latest information here in case you haven't seen it:
https://medium.com/essentia_one/introducing-the-essentia-mainnet-chain-3241747a8045