US Immigration from Japan

I'm sorry if I'm asking some things that have already been addressed on here, I did do some research but I wasn't able to find answers.

1. The online form for I-130 asks if current address is the same as mailing address, but it doesn't have a field to enter the dates I've been living at this address. Do I need to enter my current address in the address history as well in order to enter the dates of residency at this address? If so, do I enter today's date as the "Until __/___/____" date? even though I will continue to live at this address?

2. Petitioner's Parents Information: My father is not on my birth certificate. Do I leave the fields blank and write only my mother's information? If so, do I need to add an explanation letter about this or will they understand by seeing my birth certificate (included in the package)?

3. Since I'm filing I-130 online for spouse abroad, do I need to send the I-130a separately in the mail? Or do I attach it to the I-130 as a PDF file?

4. As the petitioning spouse, am I considered a "preparer" of the I-130a?

Thanks in advance!