Unlike the NY HAL, you are not trying to hatch at a particular time, just a general time frame. Setting within two days of Saturday, March 5, allows for those that get shipped eggs (not an exact delivery time is possible) or those that would be out of town/family obligations/etc for Easter could join in. Keeping an "end date: just allows the "official hatchalong participant" numbers to be calculated for the contest of number of eggs hatched. Hatching together and sharing is what the Easter HAL is about!
The cover is there because that space next to the motor is too hot....maybe someone here has successfully used it but I know the old ones didn't have the cover and the company put it on the current version. I would say if you could use, they wouldn't have bothered. I would recommend leaving that space alone and just hatch another batch after the HAL batch!
What great packaging!!!
I have not ordered from these before so was not sure what to expect. I'm going to email the lovely lady I spoke to on the phone when I ordered to thank her for getting them to me safely. 
I have mainly polish though which are not in general a broody breed. I struck lucky last summer when one decided she was going to give it a whirl.
