Bitcoin has survived for 6 years without the block size limit effectively constraining the block size, why will this established pattern suddenly reverse if the limit is maintained high enough to not constrain the block size (or removed entirely?)
Do you think the hashing power that is currently protecting the bitcoin chain would be the same if the 25 BTC subsidy wasn't there? Because eventually it won't be. I find it hard to believe that you don't know this.
That would certainly be the case, if multiplication didn't exist.
Fee revenue is (number of transactions) * (transaction fee)
Because of the magic of multiplication, having high transaction fees isn't the only way to have high fee revenue.
As a matter of fact, the producers of every product and service in the economy (except a few minor corner cases) maximize their revenue by increasing volume, not price.
The recent oil price development is a good example of how wrong your simple minded economic model can be. I advice you to look up the term price elasticity.