Tinker they have putters with two white balls on them nowadays, even three!
I'm a 2-ball guy. I'm a reasonably consistent putter overall, and I've never felt like a different putter would improve my game. It's fine to like big putters, but if you're touting your putter based on MOI I have to ask how you play golf at all if you can't hit the ball with the middle of a PUTTER.
The 2 ball is a nice alignment for me, especially with the 6ft or less putts.
Yes....multiple alignment lines, as a matter of fact. 
ZWExton most people routinely miss the exact center of the putter on many putts. Longer putts tend to cause an even bigger miss. Over the years, a large part of putter design has been trying to decrease the effect of these slightly missed strikes.
My MacGregor had an insert that is softest in the center and increasingly firm moving outward in either direction. Distance control is really good with this feature. The new Cleveland putters use different milling on different parts of the face to create the same advantage.
So the problem is much more prevalent than you think it is. I'd wager that if we had ultra slo-mo video of every out you took during the course of the round, you would be unpleasantly surprised by what you saw.
I don't think a sight line does anything for a short blade putter. I use a huge mallet head Mentorsports Triad II. It has a 1" wide channel milled down the top from front to back with a narrow sight line milled in the center of that. I find that my putting is better if I concentrate on the site line and not the putter face.
This is what it looks like-[upl-image-preview 
With my Newport, I just get the ball in the middle and hit it. I putt great with it. I just wonder if the sightlines on the Anser 2 will be a big deal to me. I cleaned up the insert on the Newport Tei3 after using it all year and the spot on the insert was as big as a thumbtack.
Yes!
If I like how a putter looks at address and I can line it up accurately and consistently, I don't mind if there's a sight line/dot/other marking or not. (I prefer a relatively traditional look to my clubs, though, so tend to stick with 'keep it simple' when I'm choosing clubs.)
Sight line.
No preference here
Never really thought about it but my Ping Ketsch has 3 of them and this has been the best putter I have ever had and I do find it easy to line up putts, so maybe the sight lines have something to do with it.
Really never gave it a second thought.
The only thing that ever mattered to me was having the putter face square to the ball and stroking the ball on the intended line at the right pace. Never put an alignment line on my ball... never did anything other than pick out a reference point on the green (an old ball mark, spot, etc on the green itself) and set my putter up square to that line.
It worked out pretty well.
rsvman I'm sure I wouldn't be surprised. I push and pull my putter so often you'd think I was fighting with it.
ode nice carpet/rug...
