Im a newbie and have a question:
1) If the difficulty increases exponentially.
2) If in the coming months "halving" will reduce to half the miner's reward.
3) If the projections of various spreadsheets indicate that it is not currently profitable mining.
How will continue to operate the system?
Many of the current hardware will no longer be profitable after the halving. So, many hardware will stop mining and the difficulty will probably decrease. Miners like the Avalon and the S7 will still be profitable and new hardware will come in. So miners will still be around for a long time