My delta contractor's saw was much better, but not perfect. I have one
of the US made ones. The blade was parallel to the miter slots out of
the box. I had a hell of a time attaching the unifence though. It
sounds similar to the problem you had. On the unifence, the front rail
is a huge aluminum extrusion. The manual shows an easy installation
technique with a t-slot machined in the side that mates to the saw.
You would just have to slide the bolts down the t-slot, stick them
through the holes on the cast iron table, and attach the nuts. That
motion should have taken about 30 seconds to complete. Instead, it
took me several hours to attach the rail. This is because instead of
machining a t-slot in the rail like the picture in the manual shows,
they just drilled two holes. This makes it impossible to get the bolts
in. After much aggrivation, i discovered what they expected us to do
now. You have to stick the nut in the now-sealed t-slot instead and
magically line it up with the hole, while holding the rail up with your
third hand, and attaching the bolt through the back side of the hole in
the table. So to save some tooling costs, they sacrificed the t-slot.
My latest project involved removing the saw from the legs, and
integrating it into a cabinet so I can have proper dust collection. I
had a hard time getting my plywood panels square so that they would fit
the saw, or so it seemed. As it turned out, it was the metal table saw
cabinet that wasn't square. sheesh.