I think that the bed placed this way makes the bedroom more narrow than it is. It seems that you have place to put the header at the wall of the window, and follow it with wainscotting, everything bordered with simple moldings, white painted or laqued, so you won't have to change the wardrove. I would add some blue with fabbrics (curtain, cushions, carpet), and add some nice pictures or details on the walls.
About the bath, I think you have enough space to put a corner shower.

Is there any way you could put in a light tube? They allow natural daylight into difficult spaces but obviously have to be placed outside and fed in. I agree with Yolanda the bed does look tight but without actually being in the room it is difficult judge if turning it to the other wall would give more room.

You need an injection of colour so it will seem strange that I am saying to consider keeping all but one of the walls white - the colour is with the bedhead wall as a feature possibly pale blue or even dark blue as you are near the sea. Consider using some wall sticker art above the headboard (white wording on dark/black wording on light if you paint the wall) there are some superb 'quotes' and artwork on the internet (www.lightinthebox.com/WallArt and www.wall-art.com are just two) or a flight of silver birds (metal wall art) would look stunning on dark blue. You need a really large mirror too, to help reflect the electric light finish with a nice large rug - think rag rug with shades of blue - to make the room appear warmer too and still allow easy cleaning if sand was brought in on shoes etc. Don'T forget Cushions on the bed an applicqued lighthouse theme on one and beach huts or deckchairs on the others would bring a real splash of colour into the room.

In the bathroom the wall looks to be green but that could be the photo if it is a colour then again I would paint it white and then dress it with accent colour - blue and white towels - the mirror over the sink would look great if you glued small pieces of drift wood around the frame (paint the frame pale grey first then pack the driftwood pieces close together) a framed print or watercolour would break up the wall space and yes, it does look as if you could install a corner shower. Hope that helps.