First, I wouldn’t worry too much about the experience of your MIL. May not be relevant to you at all.
For 1 and 2, hearing aids can slightly lower what it considers to be background noise (loud restaurants, for example), to give you a better chance of hearing close voices. It will definitely enrich your life! They (the pros) can set them up to boost soft sounds more than loud sounds. They don’t increase everything the same amount.
For 3, RITE or RIC (Receiver in the Canal) is the more modern version and two quick advantages are that the body of the hearing aid can be slightly smaller, since the speaker is in your ear, and not in the body of the hearing aid, and you can swap out the receiver ($100) if you need more power (I actually did that).
For 4, I wear glasses sometimes and I don’t have any problem, but my hair is very short. The glasses I wear have progressive lenses and a little magnetic clip-on sunglass part, so I don’t take off and put on throughout the day. Most of the time, though, I use multifocal contacts, which I love, being able to see in the distance and up close at the same time. Highly recommend the multifocal contacts.
It is common to have a trial period where you pay for the hearing aids and wear them and have all the periodic adjustments and then, if they are just not right, you can return them. Costco has a 180 day return period. Other dispensers have 30-90 day trial periods. So you don’t have to make a perfect choice up front. You can switch brands or models later once you see how it goes. BUT, your brain takes some time to adjust to all the new sounds, so what sounds terrible at first will sound very pleasant once your brain adjusts. So, some people go through the trial and it doesn’t sound perfect, so they return them and try another model. Then, things start to sound better just because the brain has adjusted, so the second one gets the credit for being better when it may have just been the brain that got better.
It is also common to think other people mumble, when you have hearing loss. If everyone else says they mumble, then maybe they do mumble.