Just a few minor nitpicks.
'denarii' is plural. 'denarius' is singular. Latin, you know. (a bit of trivia: in the old form of pounds/shilling/pence, pennies were represented by 'd', which did indeed stand for 'denarius').
'terminal velocity' specifically refers to a falling object, at the point where air resistance prevents further downward acceleration. A bullet travelling laterally is not in free fall.
The commas make it much more readable.
This sentence doesn't quite work right. Perhaps 'symbol' rather than 'symbols'? Also, a comma after 'hourglass' would make it more readable.
Typo.
Apart from that, nicely started. However, the overall problem is that the protagonist seems to be uncaring about basically everything. There's no personality showing through, nothing for us to latch on to and relate to. But I will be watching to see where this goes.