You are correct that there aren't many voice lines, and therefore that there won't be many subtitles. On a side note, I don't know if you'd be interested in the idea, or if it would be within your developement scope, but Valve's half-life 2 has full closed captions that include noises as well as speech. Things like gunshots, enemy chatter, explosions and so forth.
I had honesatly not noticed that the player's positioon relative to the camera is fixed, and even now that you've said it, my brain is telling me it's not true. This may be because of the differing zoom-levels between areas, complex vertical environments or it may just be me, but I personally wouldn't consider position relative to camera to be a concrete and easy discernable enough guide for everyone.
As for saving, I had mistakenly assumed that you were saving the player's stats, loadout and a simple level ID, with the level being generated on load. I made this assumption based on the load times seeming similar to the level-transition times, and the fact that crates, enemies and pickups change when you quit out and re-load. As that is not the case, your choice to go with the current system makes a lot more sense.
EDIT:
I'm editing this with something that I literrally just noticed. Beacon doesn't have that many instances of flashing lights. Of the few instances that there are, the only to bother me personally is the intensly bright white flashes that accompany the lightning cell storm. This particulart instance definately needs toning down.
Furthermore, with a little careful examination of the game's lighting content, it may be possible to remove all regular or overly bright flashing lights, potentially making it safe for those who suffer from photosensetive epilepsy.