It is still a conviction for immigration purposes, but as long as the maximum penalty for the offense is not more than one year, you should be fine.

Is it better to get his fiancé to USA with a tourist visa, fiancé visa, or get married in Colombia and wait there for papers?

If she gets a visitors visa with the intent of marrying your father, that is visa fraud. It would be most efficient for your father to go there,...

Can I work for 2 employers simultaneously while H1B Transfer is still in process?

The only way to work for two employers in H-1 status is if both LCAs and I-129s are for part-time work.

We took a vacation to Mexico unaware that my wife's 2 year card expired in February.

You need to contact a Board Certified Immigration attorney in El Paso. There is nothing we can do on AVVO.

Do i include the USCIS memo and policy manual while sending documents requested in RFE?

It is unclear what "policy" you are referring to. The Policy Manual is not bindin g anyone, including CIS. You simply need to prove maintenance of...

Administrative Processing?

Unfortunately, there is nothing anyone can do about administrative processing, which of course is really background checks by the CIA and FBI. ...

May you represent my sister in law as soon as posible ?

You need to make an appointment with a Board Certified immigration attorney immediately.

What are chances of my F1 visa getting stamped?

You must be prepared to prove your intention to return home after your F-1 status expires/you graduate. That probably will require a job offer...

Will my case be delayed if i inform NVC or USCIS about change in my marital status from single to married.?

Unfortunately, the marriage invalidates your father's petition, unless he became a US citizen before you married.

Who to contact when got expired stamp in my passport

You will either have to get access to the local CBP office so they can see the mistake that was made, or contact your local Congressman's office so...