Okay it's been a couple of week since I've had significant amount of time with the saw. I've played with different tension settings on the Hegner saw. Below is a picture of the bottom blade holder:
The picture isn't completely leveled but you can see the blade holder is tilted one direction. I realize that happens more when I have more than 1 turn of tension. The strange thing is it's not always tilting. And whenever I see it's tilting, I try to push it back to being straight but after cutting for a little bit, I'd check and the holder is tilted again. When I see that, the blade ALWAYS looks like a hockey stick at the end.
Regarding on-the-spot turning, I don't know why I can't do that. And it is always when I'm trying to rotate the wood counter clockwise. I have no problem turning clockwise. It doesn't help that it varies from blade to blade even within the same pack. These are the Flying Dutchman Superior Puzzle Blades. I've gotten to the point where I would mount a blade and cut a radius on a piece of scrap wood...and if it doesn't cut well, I just put the blade in the scrap pile and try a new one. I'm averaging one blade out of every 4-6 blades that I'm setting aside. I'm not saying the blades are bad, just not sure if I'm not mounting them right or the tension is wrong or something else I'm doing wrong. And this is all using 1/4" baltic birch plywood.
I read that it may be part of how a blade is made...there's burrs on one side? I can definitely feel more tug when I run my fingers on the right side of the blade compared to the left. I guess that may explain why it cuts better when I'm turning clockwise vs counter clockwise. I'll get some fine sand paper and try sanding down a few pieces to see how that goes.
Also, I've been running my saw at a speed of 700-900. There was once when I had the saw faster than 1400 and the blade broke and all the rattling spooked me so I haven't tried going so fast again. But I'll try again and report back!
As a side note, I got some 1/8" basswood plywood just to play around. It cuts like a hot knife through butter. I can also get a tighter turn...not sure if it's due to the thinner wood or softer wood. But it doesn't feel as substantial...sturdy as the 1/4" baltic birch.