What should I do if the embassy mispelled my middle name on my J-1 ?

Carry proof of correct name in your travels to the U.S.

Got my son's Birth Certificate from USCIS after 1 &1/2 waiting for removal of Conditional GC through Marriage.What it means?

if you were approved you will get an approval notice and then the new 10 year card.

Employment history for n400?

include the job that began prior to the 5 year period.

H4 visa stamping while H1 transfer is in progress?

Yes but she will only be given until September 2019 until your new transfer H is approved.

Will overstaying less than 180days on a student visa effect my CR1 spouse visa?

It should not if this is an m=immediate relative petition.

Is thrme trips counts while I’m still on J1 visa or I must finish the program first?

All trips count provided you can document the trips.

Alternatively you can just ask NVC to correct with a copy of the passport/birth certificate.

What should I write in the "explain" section for has anyone ever filed an immigrant petition on your behalf ?

that looks fine -- adding the case number

I got an EAD from my Employment Based Green Card processing. Can I start driving for Uber/Lyfr while I wait for my Green Card?

that is ok for green card purposes but if for any reason the green card got denied working on EAD would not be maintaining H-1B so would need to...

Can my husband apply for I-485 and EAD at the same time even though his H4 EAD is still pending? Thanks.

Yes he can do this but they may make the start date later.