New & need some help! Thanks!

I posted my introduction a few weeks ago, and I mentioned that some crazy guy gave a chick to my 2 year old at a farmer's market just as we were exiting the gate, so we ended up keeping it.  We know almost NOTHING about chickens, but we do know that it's a Rhode Island Red, now about 4 weeks old I would say. 

It's basically fully feathered, except for on its neck and head and under it's vent... Although, I do see short feathers under the vent now, and some trying to come in on the back of the neck, so it's only about another week or so.   It's comb has also been growing noticeably, although not huge, and turning a slight pinkish color.  Does that for sure mean that its a roo?  I know hens have combs too, and it has had tail feathers since it was just less than 3 weeks old, and they're now about 2.5 or 3 inches long.  I also see the start of wattles, but they're just on the head, not long enough to hang at all.  It also makes a "purr" sound similar to a pigeon and it randomly squats like it's trying to lay in a nest ALL the time.  I don't know if that provides any information about sexing.  I'm sure you'd need a photo.  Anyway, it seems quite healthy to me.

But I have more questions.  Since it's a single chick, several have told me to get another one or two.  The problem is, a local feed store had some 3 week olds that they were holding for someone but they said they would get more this week.  When I went today, they had 2 DAY olds.  Much too young to put in with my 4 week old, huh?  Well, I know I'm supposed to quarantine anyway, so by then my RIR will be 8 weeks and my Barred Rock little hen and Golden Comet little hen will be only 4 weeks old.  When will it ever be okay to introduce them?  Will those breeds be alright together?

And the other thing is space.  My husband doesn't want me to keep the 4 week old (almost fully feathered) chick in the house any more.  It's big enough for the dog crate, but he's afraid that it will throw bedding everywhere and just be too messy.  He wants me to put the 4 week old RIR on the well-covered porch in the dog crate with a blanket over it overnight.  I'm concerned because it's a single chick.  Will it be okay out there?  Nothing could hurt it in there, but I mean, because it would be alone and the low tonight is 60, but we live in a sort of foggy location, not far from the river and it is supposed to rain tonight.  It doesn't get wet on the porch, and I would put the blanket over the cage, but I'm concerned about moisture and temp I guess.  Any suggestions about that?

The 2 little chicks would be staying in the bathroom under a light.  It's been around 80 degrees here without it, so especially with the light indoors, I'm not worried about those two.

Sorry for the XLong post!

Forgot to mention that inside the crate is a solid floor with pine shavings, and obviously water and food, and also a little box thingy with a small opening (almost like a small doghouse) so it can get inside for extra protection.  Would I need anything else?

That's what mine does!!  After it stands up, I can see a "nest-shaped" hole in the shavings where it snuggled down in there.

I'm concerned about the cold too.  I know the bird does fine in the day when it's 70+ with no light, but I don't know about 60 yet.  But I don't know if the pine shavings on the floor and in the box will provide a enough insulation.

I also really wish I knew the sex of the bird.  Not that it would make a difference, but I hate calling it "it." :P  And does anyone know when birds 4 weeks apart in age can be successfully introduced/housed together?

Thanks for the reply.

Thanks for the replies!

I don't know if mine would mind the age difference or not, but I feel like I should probably quarantine them for at least a couple of weeks, just to make sure that the new babies aren't sick or anything... So far, everyone seems just fine!  I'm also sort of scared since the big bird looks like it could eat the little ones!

I decided that since hubby fell asleep before me, he isn't up to make sure of where the chickens are sleeping, so tonight will not be the night my RIR goes outside! lol  I would like to wait until next week when the highs are in the 80s and lows are constant in the 60s all week, and a little less predicted rain.  And by then, the lil red will be 5 weeks old, so a little more climate-hardy.  Now, I've just got to learn how to keep it from overheating. :/

As for the little chicks, I bought a plastic Sterillite tub which has about 1.5 sq ft floor, and I put about 1.5" of pine shavings in it.  I put a hot water bottle in a sock and laid it on it's side against the side of the tub.  Then, I got a 8.5" utility light with a clamp and a 75 watt reptile heat light (a day bulb and a night bulb which I will change out).  It's clamped on and turned downward against the side with the water bottle, so it's about 15 inches from the pine bedding... 12 inches if they get up on the water bottle. 

Do you think the 2 of them will stay warm like this?  One neat thing that I have found is that the 75 watt bulb seems to be keeping the water bottle very warm, so I don't have to keep re-filling it with hot water, and the chicks like to cuddle with the sock.  They get up and go eat and drink now and then, but I worry because baby chicks tend to fall asleep in the weirdest positions, and I'm always afraid when they do this under the light. 

Any advice?  Does this all seem to be okay?  I'm used to going to bed around 9:30pm, but I don't have to work in the morning, so it's 2:40am and I'm not going to bed until I feel like they'll be fine all night!  ;)  Obviously, replies are much appreciated.

After the light had been on them an hour, I checked on them.  They weren't huddled against each other or on top of the water bottle, but they were snuggled up to the bottle, about 4 inches from each other, asleep directly under the light.  To make sure they were alive, I poked them.  They woke suddenly and appeared fine for about a split second.  And then their little eyes closed and their heads fell forward suddenly and they were back asleep.  I don't know if they could be cold or just very very sleepy since they're newly hatched and it's 3:30 in the morning. 

Anyway, just to be safe, I lowered the light to about 10 inches away if they're on the bottle... and about 12 inches away if they're on the floor.  I don't have a thermometer, but it is too hot for me to keep my hand under that light on the floor of the tub for very long.  I really don't want to cook them either, but the light is only on one side of the tub.  They will wake up and move if they are too hot, right?  Or will they just cook slowly in their sleep?  These are things I need to know!

Why is this so stressful?  I have a 2 year old.  I need to get myself into the bed ASAP! :)