Can i apply for citizenship if i register for selected services since 2002 ?

There is no special privilege attached to SS, you need to await the same period indicated on the N-400 form. Goodluck.

Getting L-2 visa in London - how many days do I need to be there ?

The consulate website should provide a suitable guidance. Goodluck.

Can I tell a VISA officer that I am moving from H1B to H4 VISA for education?

Work with an an immigration lawyer for the best outcome of your case. Goodluck.

Your I-539 was file prior to expiration of your authorized stay. The decision may take more than 6 months. Goodluck.

Can a relative holding legal residency here in the U.S., live in Mexico to take care of an ailing 92 year old aunt ??

Make an appointment to talk to an immigration matter to dicuss your case in private. Goodluck.

If I work as stain witness, help USCIS witness a sham marriage organization? Can I get any immigration benefit?

You can report immigration violations to ICE, check the website for details. Its up to ICE to determine actions to be taken. Goodluck.

What is the penalty for working in the US illegally?

Work with an immigration lawyer to have this issue resolved. Did you file taxes ? Were you issued a SSN for work purposes? Your visa may be...

Going back home for a few months to renew F-1 visa, if I work for US based company from home, do I still need to pay US taxes?

Your question regarding taxes should be posted under Tax for appropriate response. Goodluck

Do I need to file amendment to my depends (h4) as I have already lca for the same location but their names was not included ?

No, you do not, as their status is not location or employer specific. Goodluck.

240.20 230.04 1yr conditional discharge i can travel out of USA?

Its time to retain the services of a lawyer to discuss this matter in private. Goodluck.