I have a new plan – Will it work? Timing issue question

[PacsMan]

I’d like to grow my flock and get 12-18 more hens. I’m thinking about buying 3 dozen RIR eggs and hatching them. (first attempt). But, where I live I can only have hens.

Can someone give me the approx weeks that the following happen?

At what age am I going to be able to tell a roo from a hen?
At what age will RIR roosters start to crow?
(And I put this in the meat chicken section for the final question)
At what age are RIR Roos big enough to cull and use for meat chickens?
How young is too young to cull a bird for meat?

Is my plan doable?

 

[obsessed]

I only raised meaties but I have some general answers to you questions.

1. At what age am I going to be able to tell a roo from a hen? IDK

2. At what age will RIR roosters start to crow? IDK

(And I put this in the meat chicken section for the final question)
3. At what age are RIR Roos big enough to cull and use for meat chickens? I think 16-18 weeks is the norm and by this time they would be crowing

4. How young is too young to cull a bird for meat? I culled an 8 wk packaging peanut. He was scrawny but he tasted like chicken.

 

[PacsMan]

Anyone else know if I can cull a RIR before (or just as) it crows and make it worth my while?