People who are citizens of the United States of America do not require a visa to visit the United Kingdom (or any part of the European Union) for a period of 3 months.
You need a Us Visa
Yes
No. Having a visa for the US doesn't grant you the possibility to enter Mexico; you need the corresponding visa from Mexico.
yes
No, you're good. Guam is a US territory, so you can go there without a visa.
If you need a visa to go to Senegal, you need to apply for it.
If you are US, Canadian or European citizen you can enter Mexico without the need of a visa.
no you don't need a visa to go to Algeria
Yes, you do need a visa.
No. If you are a foreign national you do need a student visa to enter the country and study here, or if entering the country as a tourist you may go anywhere you wish providing you do not overstay. Once in the US legally, you may travel within the US in accordance with the laws governing the issuance of your visa. US Citizens need no visas to travel anywhere inside the US.
No... that's the glory of the West baby. "We can go wherever we like."
You don't need a visa if you have a biometric (electronic chip) passport and you are staying in the USA for 90 days or less for business or pleasure travel. Otherwise yes you need a visa.