What model is your Singer avatar? I just bought one last week-end that looks very similar, although, I guess they all lookk similar from a distance! Mine is a 99, paid 50$ for her. She has been well used! A few little marks and blemishes, kind of like me:)

Less bulk and looks better

I have always done straight seams....I don't waste fabric that way!

If you are going add 2" squares in the binding, then I'd say straight seams.

There is a slight advantage to using the diagonal seam over a long period of time as it pertains to wear-and-tear... but in a pinch, I would use straight seams too!!

the seam is not so thick when you sew it on the quilt. It looks nicer in my opinion

and not as bulky.

Straight seams with 2 inch pieces have tried it and diagonal seams make mostly seam in each piecing if that makes sense

Yes. I think that when doing a scrappy binding it looks better just doing a straight seam, as if you were making a scrappy border, and then when joining the end doing a regular angled join.

I do my binding on the straight grain of the fabric, not the stretchy side and cut my strips at either 2 inches or 2 1/2 inches; sometimes I use the backing part of the quilt for binding to the front.