a few of my thoughts (don't take it harsh - just ways to get better)

1) u really need to get a GND if u want to take really good beach sunrise/set pics dan

2) i also think the borders are a bit overdone/annoying... keep them simple and don't let them take away from the picture.

3) there's too much of nothing in the skies, so it's probably better that the crop of the horizon is higher up (2/3 of the way up) to reveal more foreground

4) sky blown out in both pictures (see point 1)

5) sharpness, as you mentioned. if it's really blurry and u you don't have a good tripod, try using a larger aperture to keep shutter times lower. DOF is only really affected when there's a lot of foreground so you can re-frame with a larger ap.

6) try also to shoot to the left of the histogram (thereby underexposing a tad) and pulling it back using software. this allows u to control a bit of the noise and exposure at the same time.

EDIT
7) if you're going to have some foreground element, include it fully (stairs in pic 2) and make it a solid part of the picture. you will need to expose for it as well and set the aperture small to keep it in focus (back to a good head/tripod).