Sorry about the splash screen, I reproduced the issue and found out what caused it to not be disabled. We may re-release v0.6.2 with this issue solved shortly.
As for the line issue, I'm not sure what could be causing it. I experience no issues on my end, but it may be because I'm using a mouse (I don't own a graphics tablet). I'll investigate it as soon as I find access to a tablet, although the issue should not happen if the splash screen is disabled.