Hmm... I've played this game before, but not for very long. The first problem can be solved, I believe by scrolling using the arrow keys...clicking on the scrollbar itself will likely not work as it is not universal for all computers. I would recommend doing something like this:
SCAR Code:
KeyDown(40); //40 is down arrow key.
Repeat
Wait(50)
Until(FindBitmap({picture of the text},xs,ys,xe,ye))
KeyUp(40)
Or far more simply, but less reliably,
SCAR Code:
KeyDown(40)
Wait(pick a number)
KeyUp(40)
As for the security image, we are actually lucky because it is all the same colour and only three characters which are all letters. It will still be a challenge, as each one has the potential to be any letter. It still probably isn't a viable option...My math skills have gone to hell since march break began, but I think that you would need to document around 17 000 different images.
I hope I was helpful, and your English is very good for a second language, much better than many native speakers on this forum. What is your first language?
Edit: I have come up with a plan, it's not great, but you could try finding BMP's or DTM's of each letter at different angles. Then you could do something like this:
[scar]
var
Character1,Character2,Character3 : string;
begin
if FindBitmap(LetterA,x,y,xs,ys,xe,ye) then //Put the first section of the textbox for xs, ys...
Character1 := 'A'
if FindBitmap(LetterB,x,y,xs,ys,xe,ye) then
Character1 :='B'
end;
Like I said, not great...