#1
I just was curious on how people went about playing by ear. For me, transcribing the melody is usually really easy but when it comes to chords it seems to take me so much longer. I was just curious on what methods people used when trying to figure out the chords of a song. Personally, I just learn the melody, write down the notes used, arrange the notes to figure out the key of the song, and then try to fit those notes in the chords. I start by just finding all the root notes and then go from there. Is there a better or easier way to go about doing it? I try to listen to tell if the chord is major, minor, diminished, etc but that doesnt usually help much.
"Men profess to be lovers of music, but for the most part they give no evidence in their opinions and lives that they have heard it." ~Henry David Thoreau
#3
start with the root note, then figure out the accents. It's obviously all going to be within finger-range of the root note, so it's not exactly a difficult task.
#4
Practice, practice, practice.

After a while, most musicians get to a point where they can sing the chords individual notes in their head without hearing them out loud (I think it's just something that happens naturally). I started being able to after about 4 or 5 years of playing, and when I got more formally trained and started taking music classes in college, it became even more easy. If you're in college, try taking Ear Training I or something.