BitTorrent (BTT) price, performance and general information

...I went to: options; preferences; general and unselected start bittorrent when windows starts, but it still starts, how can I get it to stop?

I had a power failure that knocked my pc and hard drive offline. Now when I turned it back on both downloads reset to 0%. Any way to scan for the already downloaded files so I don’t have to download again?

I want to create an index of the dht but I have no idea how to scrape it.

I am trying to figure out how do bittorrent clients manage to send files to other peers who are within usual home networks with closed ports. I couldn't find any information about this when reading about the protocol.

As far as I know, a network has to have open ports in order to receive a TCP request from someone. For example, servers hosting websites have open ports and they can receive requests unlike usual home networks where they would reject any requests that are not responses.

How do peers manage to exchange files?

hello, this isn't the first time this has happened to me. actually maybe the 3rd time that computer went down, when powered back up all torrents are gone. is such a pain going back to find what has and hasn't finished, then restarting, blah blah. is there a setting I can recover last operation, or stop this from happening?