After halving, it will be reduced, therefore, transactions can become cheaper. It will happen each time after halving.
I don't follow your logic.
Fees are meant to compensate miners for the lack of block rewards, which means that the lower the block rewards are, the higher the fees will be. The block size won't likely be getting a bump in the forthcoming years, but the demand for it will continue to grow due to more user adoption, so you better expect a significant increase in transaction fees.
There is nothing to follow
But there won't be any increase in fees either, miners can't do anything about fees other than trying to organize a cartel and decide to no include fees less than x or try to mine empty blocks, decreasing the capacity of the network and forcing people to compete for the space that is left.
But I'm sure this kind of tactic will hurt the coin and the damage won't be compensated this way.