For future questions ask them here:
t/51694 instead of making several threads.
no.1 is editable in the skin.ini
[Mania]
Keys: #
ColumnLineWidth: (# amount of values)
BarlineHeight:
ColourColumnLine:
ColourBarline:
for no.2:
the image name is mania-stage-hint and there are also several lines in the skin.ini
[Mania]
Keys: #
JudgementLine: 0/1 (an additional line directly above the image)
HitPosition: (moving the judgement line up or down the columns)
ColourJudgementLine:
StageHint: (if you want another name for the image)
For making the playfield (columns) transparent:
[Mania]
Keys: #
Colour0: 0,0,0,0
Colour1: 0,0,0,0
Colour2: 0,0,0,0
...
Colour(#-2): 0,0,0,0
Colour(#-1): 0,0,0,0
The fourth 0 is the transparency control. This is the RGBA model that includes transparency, where the normal RGB model is only about the colour.