Your tank looks like a very nice start! It's been a little while since I've kept shrimp, but I've had great success with them in the past, so I'll share what I learned.
First off, it's normal for the male to be "less red". Don't worry, he's fine! Specifically, they usually have more clear marbling in their flesh than the females do. For red cherry shrimp, you'll generally only see the males and females be the same redness if they are the specifically bred "Fire Reds".
I wouldn't be concerned about the cleanliness of gravel. As long as your shrimp are healthy and feel secure, they'll run around your gravel scooping up any fallen food bits long before it gets too embedded in the gravel. I actually would recommend not even trying to vacuum the gravel since, once your shrimp start breeding, you'll inevitably hoover up as many shrimplets as you do bits of shrimp waste. I used gravel in my shrimp tanks, and just used my hands to grab fallen plant bits and did the occasional netting of larger pieces, and left it at that.
It is, however, concerning that you mention "tears" in the female's shell. That's not typical. When shrimp eat, unlike fish, they don't get "fat", instead you can see the poop in their backs, and it runs all the way to the end of their tail where it comes out, just like when you're de-veining marine shrimp for dinner. Could we get a picture of this? I'm primarily concerned since you said she was oddly active. It could just be that she's behaving oddly since she's newly added to the tank, but I've often seen individual shrimp becoming randomly super active for several continuous hours just prior to dying within 24 hours of the activity burst.
As for food, I would like to recommend Hikari Crab Cuisine as an excellent shrimp food in addition to your algae wafers. Mine have always done very well on it (I used it as the primary food for a 10 gallon colony tank, where I went from 10 shrimp to over 100 in a matter of months), and typically prefer it over algae wafers or other veggie-only foods. They also really like the biofilm that will develop on Indian Almond leaves or dried fruit tree leaves if you leave them in tank water for a few days. It's pretty cool to see the leaf skeletons they leave behind after nibbling on the leaves for a few days. Just make sure that the leaves were both grown and collected far away from any potential contaminants. I've had good luck with this seller's Indian Almond leaves: [Ebay Link Removed] Ketapang Inc | eBay Stores[/url] Once you're tank is more mature, I'm sure they'll get a lot of value off eating aufwchs and the natural tank biofilm, too. I'm afraid I don't know much about Magic Powder or Bacter AE in terms of promoting biofilm creation, though.
In my experience, shrimp are super easy to breed. The key to breeding shrimp seems to be making sure the filter won't suck up the teeny-tiny babies (sponge filters are ideal for this, but I can't tell from the picture what filter you have), high, stable water quality, and giving them lots of cover. Obviously, provided that you get additional lights to support them (even an additional couple cheap Amazon Tingkam LED strips would probably be enough in a tank this shallow), nitrate-sucking plants like floating plants and stem plants can help greatly with water quality and stability as well, in addition to providing cover; my shrimp have loved things like frogbit and salvinia (and it's hilarious to watch them hold on to the really small salvinia only to realize that they're heavy enough to make the salvinia sink - cue shrimp paralyzed by indecision until it taps against the tank bottom and trundles off like nothing happened). I've typically done weekly 30% water changes and left it at that. For you, a 5 gallon tank might be sufficient as long as you can avoid swings in water temperature and you either really keep on top of water changes or add some nitrate-sucking fast-growing plants, which aren't critical now but they'll become more important as your shrimp population grows. You might even consider something like 25% bi-weekly water changes. Chillers are expensive, but if the issue is that the water is occasionally becoming too cold and that happens somewhat gradually at a pace that a heater could compensate for, then a quality nano heater might help stabilize the temperature. If you aren't already aware of them, Drs. Foster and Smith have a pretty good selection of heaters at reasonable prices. For now, keep an eye on your shrimp for signs of stress, like hiding, and if you're seeing that a lot then consider getting a larger tank very soon since they can't take too much stress before it kills them. I'd also recommend adding some additional dense cover to your tank sometime soon to give them a little more security. It could be more wood, live plants, fake plants, whatever you prefer, just so long as it provides some nice dense leaves or crevices for them to wedge into or under.
As long as you have moderately hard water from the tap, I wouldn't be quite so worried about promoting shrimp molting. I live in Florida, where water is very hard, and I never had to do anything at all to ensure safe molting. It's a bigger concern for critters like crayfish, which I HAVE had killed by molting problems.