Robbo - you asked is Weeping Cherry usually seen with Western Daisy? I have only handled a few of these bowls over the years (they are scarce) and all those I have seen have had both patterns. However, Carl Burns (Dugan researcher) has shown Western Daisy exterior bowls with no interior design. Conversely, I believe that Weeping Cherry is also known with no exterior pattern.
Now to the question of shear marks and the like. Robbo, you mentioned that the marks on your bowl might be straw marks or stress marks. The two are caused by different things.
SHEAR MARK
A shear mark/straw mark is not damage. It is a feature of pressed glass and is more correctly called a shear mark. The link I gave earlier explains how they are caused. Shear marks can be found on all kinds of pressed glass, not just Carnival, but the iridescence can cause them to be more visible, especially when they coincide with a non-patterned part of the glass.
STRESS MARK
Stress marks are different - they are classed as damage, and are in fact, cracks, fractures in the glass.
There are many other marks that are simply features of pressed glass, often caused by the glass cooling slightly as it comes into contact with the mould.
Sometimes the iridescence has little marks and crizzles. If any re-heating is done after the iridescence is applied, the iridescence will show a "stretch" effect. Sometimes, also, I have noticed small lines in the iridescence which I suspect is caused by a temperature change somewhere in the process.
I hope this goes some way to giving you an answer.
Glen