I'm having some troubles with a more literary writing style, and I wanted to check if the following sentences are correct grammatically, and if not, what exactly is the problem and what alternatives may I find, or how can I fix it ?
Here are the sentences:
"[...] questionable and unsafe places to sleep had plunged him into a constant alertness, one that had only been reinforced when [...]"
"After what he perceived to be an uncertain amount of time [...]" the idea is that the character has lost track of time, but some time had passed nonetheless, but he is unsure of how much.
"The noise paused in front of the door" as I understand it, sounds and noises are (in the language at least) not sentient beings who can perform actions, correct ? So what would be an ideal replacement for this sentence, the idea of it being that the character can hear sounds from afar, which is getting closer before stopping in front of a door. Also, can a sound "gain proximity" ? (i.e getting closer).
"[...] he caught a glimpse of a small group of guards facing the door. Somewhere in his mind, he noted their unusual numbers, though it barely sparked any curiosity in him"
"his thoughts had been slowed down to a halt by the bland nature the days had acquired."
Any explanation or links towards articles explaining which grammar points are concerned by these mistakes would be greatly appreciated.