I can appreciate the frustration.
The G1148 was my first bandsaw. Sold it when I upgraded to a G0513.
I did not have problems with my machine. The table flexed a bit, but I got a lot of use out of the machine.
First let's try and eliminate variables.
Have you seen this video on tuning the bandsaw by Alex Snodgrass?
I have seen several tuning videos, but I like this one the best.
Alex is the only person I have seen who recommends not centering the blade on the top tire.
Can you tell where the source of the squeal?
Have you cleaned off the tires? I observe my tires get a layer of dust/grime after use. I use denatured alcohol or acetone on a paper towel. Rotate the wheel by hand.
I can imagine the original Grizzly blade not performing. I am surprised at a new Timberwolf blade not performing.
What type of blade, and how many teeth?
The saw should be able to cut 3in thick walnut with the correct blade. Fewer TPI is better than more TPI for the blade.