the max height and width from the options menu it's the minimun width and minimum height from the image, not from watermark.
If you have a 130 x 150 image, the watermark will not apply because need a minimum of 150 to be applied.
You can also make a transparent PNG to make a watermark.
No, sorry, i'm still working on it. The problem is acces to cron settings from simple options menu and i dont want to make a bad choice.
Please download this version otherwise and change cron entries to 10 minutes to avoid spamming