OF, if you keep your left hand wrist curled and don't collapse it on regular chords, you'll find it easier to change between barre and regular chords.

Another issue is that your other finger are often unfamiliar with the shapes and it puts more strain on the little finger which is weaker. If you practise playing normal chords with 2nd/3rd/4th fingers instead of 1st/2nd/3rd (chords E, Em, A, Am, C, D, Dm) then you'll strengthen up those fingers and get used to using those shapes. And then adding the barre is only a small (but significant! :-) step after that.

An alternative to barres are the 3-note or 4-note chords that jazz players use a lot, which involve muting the other strings to avoid them sounding. They have a very distinctive sound which may suit you, but it's a very sparse sound which really needs another instrument accompanying you to give it some depth.

Re fingerpicking melody, a useful ability is to be able to use open strings in the melody or fingerpicking pattern whilst playing above the 5th fret. This really messes with your head, because years of practise has taught you that you go to the next string up to get a higher note, but once your hand position is above the 5th fret then the next open string is a *lower* note! This is very effective for leaving notes ringing on and giving depth to the sound, especially in minor keys. But as I said, it takes some getting your head around...

For what strings to use for the melody - it depends on the melody! :-) But a good plan is to use the other register for "backing". So if you're thumb-picking the melody on the low strings, fingerpick or strum some backing to give rhythm on the high strings. And if you're fingerpicking a melody on the high strings, bass notes and bass runs on the low strings. If the tune goes over more than one octave, you may need to switch from one to the other depending on where the tune happens to be at that point.

Graham.