Can i convert my H4 visa (will expire in January) to F1 visa when my father is applying green card?

It could but doesn't have to prevent you from obtaining an F1.

What type of document/visa required for a domestic employee (entered on B1, obtained EAD) to travel internationally & enter US?

If you mean what does she need to return to the US, she will need to apply for a new B1 visa, like she did initially. In terms of requirements to...

I am a permanent resident w background. I want to petition for my dad and brother to visit me via tourist visa. Any risks 4 me?

There is no process for you to petition them to visit you. They have to qualify on their own. You can write a letter saying they can stay with...

Am I a citizen? Should I just apply for a US Passport? File a N400 or a N600?

Apply for passport with evidence of what you say. Faster and cheaper.

E2 through 100K investment into buying property?

The investment has to be active, so buying property is not active unless you are developing it, or doing something else that will employ US workers.

Can I travel on the old Active L1A Individual Visa with new Approved Petition?

If your valid visa is in the same category as your newly approved petition, then yes, you should be able to use the two documents to enter.

File a change of address online for him at USCIS.

Can person in B2 visa with i-130 approved file for B2 extension?

Yes she can request extension and you can explain in a letter why she is asking for the extension etc.

What to do about my I 130 pending from 3 years ?

Ask your lawyer to contact congressman office.

I have an interview on 24 June 2019 using a ds-160 created in April 2019. Do I have to create a new ds-160?

Why would you have to complement another one? If anything has changed tell them st interview no need for another form.