Originally Posted by
scottishbride
what if I don't "look American"(non-white, non-black, for example)
and I answer "YES" to the Border Patrol agent's question? If he/she
does not believe me, will I be detained and sent to immigration detention
center?
No, there are a ton of ways to establish your legal presence in the U.S. Not very hard to do if you're legit. Imagine if someone claimed to have lived in the same town you grew up in. Can you ask questions that would remove any doubt about their claim? Works in a similar way.
Originally Posted by
scottishbride
why do I get the feeling that the DHS is trying to find a way to make
every US citizen carry papers at all times? (like the former USSR or
most countries in the EU today)
You don't have to carry "papers" if you are a United States citizen. Aliens, however, must as a condition of entry.
Originally Posted by
scottishbride
also, by setting up interior immigration-status checkpoints, isn't the
Border Patrol basically admitting that they have already failed to secure
the physical US/Canada/Mexico border in the first place? 
Not everyone in the country illegally sneaks across the border. There are visa overstays, people who have failed to adjust their status and aliens ordered removed. DHS has never claimed to have the borders secured, not just because of the difficulty, but it's a cash cow they can persistently milk. If they started seizing businesses that knowingly hire illegals, we could cut down to about 12 Border Patrol Agents.
