I pretty much print everything now at about %10 infil, it all depends on how flat I need the top surface of my print, if there is only 2 or 3 horizontal shells and you are printing at 5% infill it sometimes isn't enough to get a solid top.

2 Shells is pretty much standard, I find 3 shells can be too much and cause rise even with cooling fans, 1 shell is too thin at 0.1mm, so 2 for sure.

Agree with curious, add more shells, less infill. If you are printing with your settings as you are now, it's like you are making the printer work alot harder than it needs to to print the object, even %50 infill is huge in my books, I rarely go over 25%