Will this be a PoW or PoS (or hybrid)? you state that it will be merge mineable but earning interest on funds sounds like a PoS.
It will be PoW. I think PoS and Merged-Mining are two approaches to chain security. I'm choosing MM because I think it's easier to market to Bitcoiners. 'Bitcoin + Term Deposits' is easier to understand than 'Bitcoin + PoS + Term Deposits'.
I am not trying to name drop, but check out RateCoin (XRA) project (link in my signature), it also does what you have described, you can lock selected inputs in order to receive interest based on duration of locked block.
With that said, I will follow this project and assist where I can be of help.
Good luck.
Thanks for the link. I had been searching for similar projects, and someone had mentioned XRA, but I hadn't found the link yet. I guess there are few differences -
1. PoS vs PoW(MM)
2. Likely Higher/Variable interest rates for HODLCoin
Can you tell me more about 'lock selected inputs in order to receive interest based on duration of locked block' . . . my reading of the ANN is that users received larger interest payments if the stakes coins haven't been moved recently . . but that they still available to be used if the staker changes his mind. Can you clarify if locked blocks are different and how that works?