Your written English, though mostly comprehensible (like my Polish, for that matter) reveals many common errors.
I know. I'm only b2 level. But I'm glad that it is at least comprehensible. :)
generally, poles are pretty blown away if a foreigner so much as utters 3 words in polish in the same sentence. don't know why that is, but it is. they also tend to reeeeally exaggerate a foreigner's polish speaking abilities, again, don't know why that is.
Polish people appreciate the efford that someone wants to learn Polish. It is always a sign of the highest respect paid to the people of another country if someone tries to speak their language. So why are you supprised by the positive response?
As to whether or not I managed to understand spoken Polish
The problem is that languages in general have some amount of specifics sounds which are hard to decipher for an unexercised ear. Also the accents don't help. I can't understand too much of British (except BBC) while American English of Northern states is not such a big problem. In Poland there is no a variety of accents now but people speak fast or mutter, and the syntax is quite free.
ZiemowitEverything is base on the individual preferencies. My teacher adviced us to learn whole texts, while I prefer to learn chunks and sentences. I make flashcards with sentences - it also gives me a feel of somekind of a game.