Hi, They sWould be fine hopefully,
After the egg is is laid, the male will sometimes try to cover the egg with hay/straw/dirt/leaves, or whatever he can find. If you planing to using a incubator, the egg should be collected as soon as possible to avoid soiled, stepped on, or broken.
The female emu will lay their egg aprox. every 3-4-5 days.
if the female lays every four days, she most likely will continue to lay every four days.
The time between egg laying could vary.
Female emus generally lay their eggs at dark. So if you collecting in the morning they should be fine. But try to giv them lots of hay or straw so they can cover it up.
About cracked eggs I had some damaged egg before and I used super glue and surgical tape. Out of 4 cracked egg two hached, not bad hey. But you have to use your judgement to see if it's viable.
Hopefully you will have some more answers in here so you can hear different opinion and decide what is the best option for you