Dental care for cats and when to get help+ other questions

Hi! I’ve got an eight month old neutered cat who weighs around 9 to 10 pounds. He’s gotten all of his shots excluding the FeLv/FIV( Or something like that, can’t remember) because it was not recommended by my vet as he is a strictly indoor animal. We think he’s an ocicat because he’s showing a lot of the features, personality traits, and identifying marks of one but he was found on the street so I can’t be completely sure. He eats fancy feast kitten wet food once every night and meow mix dry kitten food is out always with his water.

Anyways, I have a few questions about cat care because no one in my family has ever owned a cat before and vets are hard to come by in my area, so I’d like to get a second opinion on some stuff.

First and foremost, I am not sure what to do about dental care about cats. My family had made mistakes with our dogs because we thought animals don’t need brushing and a milkbone/dry food would clean everything; that went as well as you’d expect. So I’m wondering what a dental routine for a cat should even look like. My vet told me to get crunchy treats meant to clean teeth but past experience tells me that those snacks are never nearly enough. I’ve also been looking but I’ve only seen tooth brushes/tooth paste for dogs, can I use them for my cat as well? Also, how do you know when a cat needs to go in for a dental cleaning? His breath is starting to get a little stinky but I’m not sure if a little stink is normal or a sign of something bad.

My second question is, should he get the FeLv/FIV shot? I’m not sure what it is but an injection offered is one that’s important right? My vet said since he’s strictly indoors that he doesn’t need it.

My fourth and last question is, can I shave my cat? He hasn’t started really shedding but I assume that when he starts, he’ll blow his whole coat out. He gets overstimulated very easily to where brushing and sometimes petting is too much, and I’m afraid he’ll get hairballs because he is a very fastidious groomer (plus I’m not a huge fan of coats being blown out all over my clothes). I was planning on taking him to a groomer so they can groom and shave him, and then I could use this grooming glove for short haired animals for when the follicles or whatever falls out. My thought process on this is that even though the hairs will be annoyingly smaller, hopefully the bulk of what’s swallowed will be smaller too and that grooming over will be quicker compared to 20-30 minutes with a furminator where I won’t even get much of the excess fur because of his fidgeting.

Anyways, thank you all who reads this and very thanks to those who respond!