Pronunciation of "botas" is off. Unless that's the way they pronounce it in Portugal...
It's spoken with an open O, the same as in "pó" (dust) or the English "boss".
Yes, there is. The verb is definitely singular, though. Yet another time when, rather than relying on what I heard the first several times at normal speed, I slowed it down in order to get the right answer. This one is the worst offender so far, I think.
'These' implies the object or what youre referring is close or near the person speaking. 'Those' means the object or whatever is not near the speaker. It would be easier to know when to use them if there were pictures along with this lesson.