What I did is try to take the top players from each period (in terms of fielding) and compare them. Let me go with your questions one by one.

1) Win shares are calculated by taking the events that occur on the field and assigning value to them. Three win shares equals one win. A part of that process is a normalization process, so more than any other metric currently published, win shares are normalized for eras.

2) Bobby Grich is a very prominent part of my next book, "On the Outside Looking In" about the Hall of Fame.......

3) Like I said above, I chose one person per era. Collins was a good fielder for a long time. His career total is high, but the per 1000 innings rate is on the lower end of the list I gave. Collins is probably the best overall player in terms of balance between hitting and fielding.

Just remember the key to all fielding metrics is to leave aside the style and arrive at the substance. Few looked as good as Alomar making plays, but the he didn't make as many as some other second basemen.