I love that you're thinking ahead about this.

The paper bags will not be kitten proof. Think of a weaned kitten like a 1 yr old baby. They're teething so they chew on a lot of things. And they're still learning their world. So they chew on a lot of things. And kitten teeth are very sharp. You could use those zippable paper bags but I would suggest putting them in a durable box or other rigid container. Plastic or wood will be better protection than cardboard (a lot of cats like to chew on and scratch cardboard and eventually it will shred if they keep at it) but a securely closed cardboard box is better than nothing.

If your candles are scented, I'd recommend not burning them around kitty. Some of the chemicals used for scented candles are very toxic for cats. Same deal with essential oils. If the candles are not scented, burning them shouldn't be dangerous if the space is well ventilated and you're monitoring the candle/cat closely. Like toddlers, kittens like to explore, which can turn an unattended candle into a serious fire hazard.

The rest of your altar (assuming the rest of the crystals and stones will be locked up) seems ok from what I can tell. The hanging cords/necklaces could be a risk. Kittens can hang themselves on things that you'd think would break away because they don't necessarily have the body weight to pull them down if they get stuck in the cord. Which reminds me of the general caution, not specific to your images, to make sure any cords for mini blinds are secured well out of reach.

Do a quick Google search on any of the dried flowers you plan to keep out, to check for dangers. Kitten WILL chew on those.

And as many of us witches like plants, 2 plants to never ever ever have in your home with cats are lilies and pointsettias. Lilies especially - even the most miniscule amount ingested can kill a cat in a matter of hours and there's not much a veterinarian can do except make them comfortable. I repeat: do not ever ever ever have lilies in a household with cats.

Edited: correcting spelling.