#1
I've never heard two downloaded songs that play one after another without having a little "bump" between em.
#3
it depends on the ripping of the song in first place.

in itunes (if you use it) try the gapless album option to see if that helps

other than that, use torrents, they usually flow really well

or buy the album if the band merits it
#6
Quote by cedaguol
it depends on the quality of the player and the computer i think

Nope, it's unavoidable. It's something about the way mp3s are written, there's a lump of non-audio info in the end of each track or something like that which prevents mp3 players from playing series of mp3s continiously.
I'm a communist. Really.