I have a few Q's.

Also - a few of the birds seem to do a little bit of a cough, thinking they might have a cold. Are there vitamins that can be added to their water to help them recover or is their something I can "whip up"

Yep, i can't find the name of it now (we have it around here somewhere though), i think it was a powder that you add to their water. we have used it when chooks look abit off.

Also - Scraps, the girls don't seem interested yet in scraps but are there things they SHOULD NOT be fed?
and - I have been covering one section of their run where I keep their feed because its been raining and I don't want their food getting soggy. Do chooks care about soggy food?

Chooks don't like similar foods that shouldn't be given to dogs or put in the compost- onion skins etc

You don't want their food to get wet cos it can get mouldy or start to grow (especially if it a seed mix).