project sounds interesting, but i wish rewarding system would be spread more towards rewarding long time holders/MN owners
Doing so will make it difficult for new investors to join. An example to what you mentioned are masternodes, which kills any chance of investment when the price goes up. On the other hand, we have PoS where everyone can invest as much as want and still make profit. PoS is more sustainable and encourages not only long time holders, but new investors to hold as well. If you have a vision towards the future of DeepOnion, this article might interest you:
DeepOnion's 1% PoS = Financial Freedom