1. You do not "need to" BUT I would, your paying for it in the $1070 I-485 fee anyway and you will need it prior to filing for the SSN Number or renewing your TX DL at DPS.
2. I would not do it my self. You can, but its always better to have a certified translator do it, takes away the doubt by USCIS.
3. You need to go to the USCIS website, www.uscis.gov, click on forms, click on I-485, look for lockbox address and thats the proper address. All applications are now centralized filing nationwide.
I agree with all my colleagues, I think its misguided to file your application and not have a competent immigration attorney at least review your paperwork for a nominal fee and make sure your not wasting your $1490 filing fees. BY law USCIS is NOT allowed to refund fees. I believe the only exception is if filing premium processing (not applicable to you) and they do not process the application within the timeframes set by law.
If you make a mistake on the applications, the best case scenario is they reject the application and send it back to you for correction and refiling. The other possibility is your case gets denied and the fees are lost. The worse case scenario: You get denied and if you are no longer in your own independent legal non-immigrant status (F-1 out of stay for instance) then you may end up in deportation proceedings when the government issues an NTA-Notice to Appear to place you into deportation proceedings. Also, since you are an F-1 student, you are monitored by ICE in the SEVIS system NOT by USCIS. ICE is very trigger happy and will show up at your home at 5 AM to detain you "IF" you are out of status on your F-1. IF NOT, then of course your fine and nothing will happen.
Immigration forns are deceptively tricky and seem easy and self explanatory BUT you are signing these forms under penalty of perjury (potential criminal sanctions). Make sure your doing it the proper way, thats my best advice. Good luck.