I have noticed that the white walls in SketchUp looks very grey when you see them from a different angle. It wasn’t like that before. I liked it better before.
I also wonder why there are dots/very visible corners in the newer versions?
hmm. nothing has changed in these regards.
it’s probable you have different light & dark shadow settings than you’ve had on other Sketchup versions.
http://help.sketchup.com/en/article/114934
re: your second question. again, nothing has changed. you just have end points turned on in your style. Window-> Styles
Aha! How stupid of me. 
Thank you so much.
Can you please resend that link, it is broken
https://help.sketchup.com/en/sketchup/casting-real-world-shadows
if you don’t see the dark / light parameters in the panel, first click on the small black and white + button top right corner.