Question About Tooth Implants With No Crowns

Note: I tried posting to r/askadentist but got no responses, so I figured I'd give this one a shot. Thank you for helping!

So I had tooth implants for two missing teeth completed about a year ago, but never got the crowns; I was able to pay for them myself out of pocket in Mexico at the time, but it was a bit of a traumatizing experience (long story short, dentist dropped a drill down my throat, almost died, but I'm OK). So I spent months getting insurance on ACA, only to find out that my premium is now going from $8 to $700+. In other words, I will have no insurance.

I know that complications and teeth shifting can arise eventually, but it will likely be quite some time before I'm able to get the crowns, if at all. Thankfully, they are back teeth, so my day-to-day is currently unaffected. I have two immediate concerns I'm curious about -- I appear on-camera and use my voice extensively for my career, so frankly, preventing bone loss and a deviated septum are the reasons I got the implants in the first place, as I don't really mind missing a few back teeth. So:

1. Will having the implants in the bone stop the bone density loss associated with missing teeth?
2. Similarly, will having the implants in the bone stop the acceleration of a deviated septum? My dentist said I was at the beginning stages of that, but it's not problematic so far, and a very common thing; if it gets worse, that would be big trouble for a job that requires stringent breathing techniques.

Appreciate you in advance, I'm going to at least try to get one dentist appointment in while my healthcare is still active, but having some answers could really help my stress levels. Grateful for any guidance.

Demographic Info:

Male, age 40, 6'4", 187 lbs, nonsmoker, no regular medications, no serious previous medical issues.