All of the breeds you ave chosen are friendly with people and have a generally good temperament with each other. You wont see any squabbles to establish pecking order for many months so I wouldn't worry about that too much. Besides, growing up in the same brooder together should help them to establish bonds with each other.
As far as them dying from diseases, I would personally start by ignoring mean spirited comments. Then I would make sure that I have the proper brooding equipment.
Feeders/Waterers- your waterer needs to hold enough for all of the chicks and will keep them from falling in a drowning. The feeder needs to keep the chicks from jumping in and pooping all over it. Usually the little plastic
1 quart feeder/ waterers are great for your first time around. Just steer clear of things like dog dishes. Chicks can fall in and drown, poop in the food/water, or knock it over and get trapped underneath.
Bedding- pine shavings work great as you can put in 1-2 inches and skim off the top layer of droppings every day. Never use cedar as this can cause sickness and death in small animals. And steer clear of slippery surfaces, such as newspaper, as this can cause spraddle leg.
Heat source- make sure your
heat lamp is at least 100 watts. They are easy to obtain at
Petco or
Petsmart in the reptile section. I use Flukers brand light fixtures, they have a dimmable fixture. Make sure you buy the red heat bulb, also in the reptile section. If your chicks are clumped under the light, they are too cold. If they are all clumped as far away from the light as possible, they are probably too hot. Your chicks should be exploring the whole brooder, eating, drinking, and napping occasionally!
Chicks being shipped- CALL YOUR POST OFFICE! It is very important to call your post office at least a week before your chicks are shipped to let them know they will be there soon. Also, call the day your chicks are supposed to arrive. My *very first* chick shipment arrived and ended up staying over night because the phone number on the box was one number off. I called the week before but assumed that everything was OK even though I had not received a call the day of delivery. They ended up bringing them to me the next day but they were nearly dead. I lost all but 1 out of the 5 that I had ordered. I should have called the
day of to check on the delivery status of the chicks.
I am sure there are lots more questions you have and I am sure you can find lots of help and answers on this forum and in books. I suggest "Keeping Chickens with Ashley English" as a good book to start. Ashley gives great practical advice for first time chicken owners and even a whole plan for building a chicken tractor and nest boxes. I found, and still find, this book to be both a pleasant and helpful read.
I hope this helps and feel free to ask away! Don't let the forum labels fool you (mine currently says "New Egg" as some of us have done this for years and have only become members recently)
Happy Chickens!