1. I purchased some sweet PDZ from TSC and i'm curious on how I add it in to the coop. Right now there using shaved pine for the interior. The coop doesn't smell horrible all the time but it has its days and pine shavings are getting gross after like 2-3 days so I wanted to know should i take out the shavings or go like half and half?
You can sprinkle a little PDZ onto the pine shavings if you wish. Stir up the bedding. If it's stinky in the coop already, you may need to look at your ventilation (need more fresh air?) or clean more often. PDZ works well on poop boards and make it's easy to scoop poop from under the roosts.
Do you have photos of your coop?
2. I brought a large bag of chick starter when i first got the chicks and actually i think it might last until there 6 weeks or maybe late 5. When that runs out what food do I buy next.. i saw in TSC there was Crumbles, layer pellets and something called scratch. Which one would be best? They are all pullets so i would want to feed them something to help them lay but i don't know if 6 weeks is to early for that.
All of us have our own thoughts on feed - just look at all the threads.
This is my 2¢ on feed
- Leave them on chick starter until they all reach point of lay, then switch to a layer feed. Your chicks are only 5 weeks old, they are still growing - you have a ways to go.
- Use an all flock/flock raiser feed - this can be fed from now on (chicks to old hens and roosters) Provide oyster shell free choice for actively laying birds
- Personally, I use an all flock feed, sometimes chick starter, but mainly all flock year round.
3. How do I get them back up the steps? they are coming out easily but i have to catch them every time i wanna put them back in a little prematurely because they seems to ignore my calls for the most part while in the run.
Sounds like normal chick(en) behavior - ignoring calls

To get them to come, get yourself a little can or container.
Put a very small amount of scratch, mealworms or favorite treat in it. Something that rattles. Shake your can and call. It won't take long before they associate the can (noise) with a treat. Give them a few bites of the treat for coming to you. Sort of like you would a dog
4. Should I keep additives in the water. Do I need to buy more or was that just a baby chick thing? I heard that some people keep Apple Cider Vinegar in the water but not sure why.
For me, fresh clean water daily is best (cleaned water stations too).
It won't hurt to keep some electrolytes or poultry vitamins on hand for emergencies.
I'm not a fan of water additives but will occasionally add probiotics or similar to water for a couple of days here and there.
Hope it all helps.