When "more" is used before adjective or adverb as "inconvenient" in your example, it is an adverb whose primary function is to modify the following word. However, when it is used before a noun (or sometimes after a noun), it is used as a determiner or adjective. For example: I need more money. More context is required. I need something more (to eat). In the above examples, it means: greater in ...
Hard to say. One would have to know a lot more about 19th century books on usage than I do in order to determine whether "the more" was perceived at the time as being supplanted (and there was an effort to preserve its use). But 'the more' has long been in natural use with the comparative.
What's more is an expression that's used when you want to emphasize that the next action or fact is more or as important as the one mentioned. War doesn't bring peace; what's more, it brings more chaos. Or your example.
How to use "what is more"? - English Language Learners Stack Exchange
"More likely than not" logically means with a probability greater than 50%. A probability of 50% would be "as likely as not". But the user of the phrase is not making a mathematically precise estimate of probability. They are expressing what they think is likely in an intentionally vague way, and it's misplaced precision to try to assign a number to it. As an opposite, one could simply say ...
"More likely than not" - (1) How likely is it for you in percentage ...