Edge of window tilted towards window - Damp

[FerrersWay]

Hi,
I've got a problem with damp under the bay windows of my 1900's ish mid terraced house that I'm trying to track down.

Now I am only just starting my DIY career (first house), so please forgive my lack of knowledge. A bit of plastic slopes backwards towards the bottom of the window, which combined with old silicon sealant and cracks (pic 1 & 2) I think is leading to the water getting below the window frame and into the wall below.

My question is have the windows been poorly installed and what should be done about it? Would re-doing the silicone fix the problem and do I need to do something about the slope? I've also noticed big gaps between the frame (pic 3), are these normal?

 

[DHFrames]

Can you put more pics up from further away

 

[FerrersWay]

Here are a couple from a bit further away, cleaning/repainting these is definitely on the todo list for some point!

 

[foxhole]

Damp under windows is usually condensation caused by lack of adequate ventilation.

 

[FerrersWay]

Damp under windows is usually condensation caused by lack of adequate ventilation.

Is that from condensation on the windows running down and onto the wall below?