To get the driver licence.

Check with your local DMV regarding their requirements for issuance of a Drivers License.

Was there such a period ?

The period of illegal presence accumulated between the denial of the I485 and the time he left the country.

Can i reapply for aos after denial?

With the I-130 being withdrawn, you have no basis for AOS.

Last three years of tax return transcript.

Visitor's visa extension issue - what to write in the letter just for vacation or want to search the universities here?

Your answer needs to reflect the truth or you can be on the line for fraud.

Am I out of status because of the 90 days unemployment rule during the OPT ? Do I need an immigration lawyer ?

Make sure you talk to your DSO and you may also need to contact an attorney.

I-485 filed, but noticed that i-94 has different name (extra middle initial) than that of passport.

Your lawyer knows more about your case than any attorney on this public forum, I would assume. Therefore, maybe you should trust your lawyer.

You should contact a patent attorney, but if you are an LPR, you should be fine.

How long before I get answer from USCIS if I was approved for green card? (My husband is petitioner for me)

It could take at least two months. These issues usually take time to handle, you should consider contacting an attorney.

Vermont center...

It should take at least eight months, so arm yourself with patience.