In Russian similar word "доставать" means either "to get something out/from something" or "to reach out to something". But in sentences of this lesson "dostac" is used in a meaning of plain "get/receive". Is it always so or is it just a simplification?
For a lot of people, there is none or almost none. Well, "ę" is a nasalized "e", but if it's the final sound of the word, many people just pronounce a normal "e". I guess it's safe to nasalize it just a bit, but not overdo it.