This is a known issue that Adobe is investigating. Please read this reply from Anshul_Saini  .   Peter ... View more

Go to Preferences > General and see if Keyboard Increment is set to a very small value or 0. If so, increase it to a useful value.   Peter   ... View more

This is a known issue that Adobe is investigating. Please read this reply from Anshul_Saini  .   Peter ... View more

Unless there is some particular reason to use the Paintbrush tool, I would suggest that you use the Pencil tool for such superfine strokes. I don't know what the lower limit is for the stroke weight, but I have just set it for .01 pt, and while it's quite difficult to see at 100% it has none of the blob problem that Jacob (Hi, Jacob!) mentioned. Make sure, though, that the Brush Definition is set to Basic (i.e., no brush).   Unlike the Pencil tool, the Paintbrush requires a brush, so as a test I created a Calligraphic Brush with a diameter of .01 pt and set the stroke weight to .01 pt, which resulted in a heavier line than the brushless pencil stroke at .01 pt, and it had the blobs.   Peter ... View more

1) Select all the dots. 2) Go to Object menu > Compound Path > Make. 3) With the Compound Path selected, apply the desired gradient.   Peter   ... View more

The problem is not universal: I've opened your test.svg and do not see the hairy ball — all paths are smooth, whether in GPU or CPU. Possibly another app conflicting?   Peter ... View more

This type object has no attributes. Each individual letter has the same color blue applied at the character (not type object) level, as is normal. The W has an opacity of 10%, the R is at 50%, the O and D are unaltered. The Layers panel shows no attribute applied to the object, which is literally true. Are opacity attributes applied to the letters? Yes and No. Here an opacity of 30% is applied to the type object, which is indicated in the Layers panel. The W, which was already at 10% is now reduced to 30% of 10%, or 3%, and the R to 15%. While in my opinion it's not a bug, just the way it works, you are, of course, welcome to go to https://illustrator.uservoice.com/ to report it or to enter a feature request.   Peter ... View more

Object menu > Expand, then Object menu > Clipping Mask > Release. Select and delete the no-fill/no-stroke rectangle that now sits above the objects.   Peter ... View more