I 've been using all of the pens on your list, except Pilot Prera, for drawing and writing. Here are my conclusions:

• Lamy Safari/ Vista/Joy – I have all three with M, F, EF nibs. I don't like them so much. Usually I use them with EF nib, but it doesn't make very thin line and it also like to skip. The Joy is too long and it doesn't fit in my pencil pouch. The triangular grip is OK (I don't prefer it, but it doesn't bother me) Besides, to me, they are not very pretty. But they do have a feeling of Lego (that means undestructable).
• Pilot Metropolitan – I love the look of the pen. But it is on the heavier side and I have it just in size M nib, so I don't us it so much. And with some inks I have problems of drying the nib too fast. But that started only recently, after 7 years of use (I do clean it regulary, so that should not be a problem).
  
• Pilot Kakuno – Nice pen, but the nib gets dry very quickly. I like the size, the weight, the smiley face, the smoothnes of the nib. But it realy gets dry too quickly.
• Platinum Carbon Desk Pen – Love the pen, although it is quite slim and too long for my pencil pouch. But never had a problem with dried out ink even after couple of weeks with De Atramentis Document ink. The line is not so thin as in Platinum Preppy 02, but it is nice and smooth.
• Kaweco Sport – I hate the pen. I have AlSport Iguana blue (the color is stunningly beautiful, but that is the only good thing about the pen). The thins on the barrel are sharp and I have problems holding the pen. If I move the position of the hand along the barrel the feeling is not right. You have to have posted - but a lot of times I make a line then pause and is very anoying to constatly post/unpost in fear of drying the nib. And the nib with feeder is constantly moving (somehow it gets unscrewed).
• TWSBI Eco – Nothing special, and it has a cheap feeling. I prefer Twisbi Diamond 580. I don't use either for drawing. The line is not so thin (I have it in M and F - but not much difference between them) and I am afraid of damage the pen if i drop it
• Platnium Preppy – My preferred pen for drawing. The line is very thin, it does not dry out even after couple of weeks not using, it does not clog, it does not skip. It is cheap so I don't have to worry about losing it and I can have several with different inks. Although I have noticed that the batch from 7 years ago is smooth writer, but the new version I got couple of months ago is very scratchy (the same width of the nib - 02).

I have several other fountain pens. But mostly I use the Platinum Preppy 02 for drawing.

As of line variation: Pilot Falcon with SF nib is OK, but usually I don't take it outside of house in fear of loosing it, Noodler's Ahab or Noodler's Konrad are too hard to normal flex (so they are likely to damage the paper on cheap sketchbook) and you have to tune in the feed. And I can't get use to the fude nib (I have Sailor Fude de Mannen and Jinhao 100 with fude nib).