V13 P1, 48%
I’m pretty sure I would’ve been the end of me if I fell by myself, after all."
I -> it
V13 P3, 5%
"Yeeeeah, I’d say we’ve another flash flood in our future,"
I'm of two minds on this one, but as I did a double take I thought I'd include it. If speaking generally, I think the wording works as is (eg, flash floods will happen, regardless of their actions). If speaking specifically, thinking through the outcome of taking the river option, then I'm leaning more towards the wording: "I'd say we'd have another flash flood in our future"
20%
"Thankfully, I’d had plenty of mana left over since we hadn’t run into a single monster along the mountainside path."
Tenses I'm unsure of again, but I think it might work just as 'I had'
44%
"The door opened slightly every time a gargoyles attacked, so we’d probably be screwed if all six crashed against it at the same time"
Either 'a gargoyle' or 'the gargoyles'
88%
"There were obvious indications that the door and window had been a slapdash job, but overall, this place looked like a real house."
IIRC from part 1, the house had multiple windows. Of course Nao might just be referring to his current perspective, only seeing one of the windows from his point of view. Otherwise, 'window' -> 'windows'