I-140&I-485 concurrent filing

I'm going to file NIW I-140 soon, and will submit I-485/I-131 later since I
have not got my Medical done yet.

Form I-140 part#4 question 4 for "Are there any other petitions/applications
filed with this Form I-140", what should I put here? I guess it should be NO
but when I later submit I-485/I-131, will this dis-qualify myself as concurrent filing? And if put NO here, should I mail my package to POBox 852135?

Then should I mail I-485/I-131 to this POBox 852135 later on?

I heard that as long as I-140 is not approved than I-485 belongs to concurrent filing. Need NIWer's expert input on practical operation here. My intention is concurrent filing, but can't get all I-485 paper work done timely.

Here is what USCIS WEB states:
http://uscis.gov/graphics/formsfee/forms/i-140.htm

For I-140s filed concurrently with Form I-485:
USCIS Texas Service Center
P.O. Box 852939
Mesquite, TX 75185-2939

For I-140s filed alone:
USCIS Texas Service Center
P.O. Box 852135
Mesquite, TX 75185-2135

Another issue, should I submit I-1485 first and after get case# to file I-131
later?

Any input would be welcome.

Thanks for your help.