I agree that two roos can live together, but disagree about them only having issues if there is ladies to compete over. Just like us, they will sometimes have disagreements with their room mates. Sometimes it will escalate way beyond what is acceptable. Yes, I have 4 roos living in a stag pen with the ladies next door. In addition I have seen people who keep two roos in their breeding pen without issues. Every situation will be different.
It's the being in constant contact with their weight on their feet. It more of an over use on hard wire than it is about the wire actually making instant cuts. It's long term exposure of them placing all their weight on their feet. And Poo gets stuck in it instead of falling through, depending on how large your opening are, even 1/2 inch. I imagine chicken poo is a bit larger than pigeon poo. Larger diameter wire will probably hurt less than than thinner diameter as it spreads the load out a little more. Chickens like to scratch and they are practically hatched doing so. It's so cute to see how naturally it comes to them. A wire bottom will never work well long term IMO. They need a flat bottom with shavings or other bedding. Think, a shoe doesn't cut you foot... but pace a round in it long enough it can rub sore spots that develop into blisters and eventually wounds we might call cuts. Similar type thing.
Well, now you have BYC too. And you will get lot's of answers and opinions as what works for some simply will not work for others. We have different set ups, environments and perspectives.
PDZ is a horse stall freshener. I believe it's derived from natural minerals, but not 100% sure. It works really well to absorb ammonia smell. DE is diatomaceous earth derived form dead diatoms that have microscopic sharp cutting edges is used for some absorbent things and to cut micro scratches into insects. Beware of the FALSE uses people tout. It is also used to keep feeds from clumping. DL is deep liter. Here is a link to an acronym list for your future reference...
https://www.backyardchickens.com/articles/acronym-list-for-byc.64740/
Fermenting is as simple as placing feed with water and let it sit a few days until it sours, then feed it out before it sours too far.
I'm pretty sure Aspen is a brand name that sells both cedar and pine shavings.
As far as a hen goes... first of all I would quit buying birds at that auction. People take birds to auctions for a reason. Very often illness can be spread and you DON'T want to bring it home to your place. (Ask any number of people who have dealt with it). Second, if you want a hen to brood then it must be a broody breed to help ensure your success instead of frustration. But let's be honest... all this going on in doors seems like a nightmare. If your place isn't big enough to have some outdoor access, I might reconsider waiting for a new situation. A pigeon is one thing, a CROWING rooster is another. And if you think they ONLY crow when the sun comes up, think again! They crow to compete for the ladies, to warn predators, because they heard something, because a light flashed, for no reason at all. Mine start crowing around 3:30 EVERY morning! Might be a problem if you have neighbors. Maybe you will use a crow collar? Ya, I wouldn't be inclined to do diapers either.
Anyway, your friend is partly wrong about roosters killing chicks. A teenager, that's different. But a rooster will protect chicks as they are very likely his offspring. He will call them to treats and protect them. It really is quite a special thing to see! Any roo who attacks chicks is NOT welcome here, and I don't really ever have that issue. But what will you do with the chicks and extra cockerels that you get? Hatching comes with a fair share of responsibilities. Will you be OK if someone is going to eat the males they get or must they ALL find happily ever after homes for you to be happy? Mama hen will not be satisfied to just sit around, she will want to take her babies out exploring and teach them to forage. You may be able to sprout or grow fodder to help with enrichment. I'm certainly not saying it can't be done, just that there will be plenty of challenges. My birds all eat the Purina flock raiser crumbles which is 20% protein and only about 1% calcium with oyster shell on the side for layers. If I was only buying for one boy, I might consider any grower/raiser/finisher (really all just confusing words) that has about 18% protein and still 1%ish calcium. In addition, I would consider going in on a bag with someone or buying smaller bags if available as the farther it gets away from mill date, nutrients do diminish, according to studies.
I do usually recommend friends. I personally would consider keeping him single. Yes, they are social creatures. They can socialize with you and still be content, depends on the individual. But while getting him a hen might make him happy, doesn't make it fair to a hen per say... I don't know for sure what I would do, but putting the thought process out there for you anyways.
Sorry if these have already been said... I'm still catching up to the end of the thread.
OH BUT WAIT... there's more! If you think poo smell is bad now, just wait until the first time you smell a broody poo!

they are every bit as bad as having a dog poo right next to your head. Because they will hold it the whole time they are sitting on the nest and run out once or twice a day to relieve themselves. Will she be able to get far enough away from her nest to be comfy doing that? Yes, way too much info inside my head.