Both of your examples
This is done easily.
This is done more easily than I thought.
are grammatically correct.
However, I would personally consider both sentences to be slightly awkward or incomplete, since you could express the same ideas using adjectives. If you had no more details to add, then more natural expressions might be
This is easy.
This task is easy.
This was easier than I thought.
This job was easier than I thought.
The original examples would also be fine if there were more details to complete the sentence, so that there is a reason to use the adverbial form rather than the simpler adjectives that I proposed above.
Calculating this antiderivative is easily done using integration by parts.
Calculating this antiderivative is more easily done using a trigonometric substitution.
Horror is not an adjective. It is a noun. In the sentence "I saw a horror movie yesterday", it seems like an adjective, since it modifies "movie", but that's not what's actually happens. "Horror movie" is a compound noun. "Horror" can also be a noun by itself
Hey, could you recommend some good horror for me?
You could also substitute another movie genre for horror in the above sentence. Action, adventure, comedy, drama etc. and it works the same way.
Adjectives similar to horror are
Scary, creepy, unnerving, unsettling, disturbing, frightening, horrific, terrifying...
Best Answer
If we use rudest here, we would have to still use "most" for the other adjectives:
The title uses "most" to apply to all three adjectives, because "ill-Manneredest" is a word I've never seen nor would wish to see in a title, unless written in jest, and there's no "humiliatingest".
Hence, the most logical, or logicalest, way is just to attach "most" at the start of the title.