Nice shots, like the framing. Really like the 1st a lot , the 2nd one I would crop out the rock on the bottom - but that is just me.
RE: the smoothing effect, it is all in the eye of the beholder how much is wanted - I know some photo guys that significantly dislike "blurred water" shots - I happen to like them very much.
A lot depends on exactly the motion of the water, with additional time you don't always get more smooth, sometimes you would get more "white" and softness. 5 seconds is a long time. Every little drop sprayed up would is a white streak, more time = more drops = more streaks, enough streaks and "white" & perceived softness happens. So, if you can, return to the same spot and speed up the shutter and open the aperture and see what effect YOU like - 5 seconds, 2.5, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60th. If you move fast you might have all of a minute invested in the experiment.
As some shutter speed and precise condition you can get a real motion feel to the shot - if that is what YOU like - the more violent the water movement, spray, desired effect will change the combinations YOU want. Find other more violent moving water and do a couple of these 1 minute experiments and find out what you like for each circumstance.
Everyone likes something different and you can't please everyone - this forum is really great for tips and techniques to achieve what you want in an image.
The ND filter helps with being able to get shutter speeds and aperture values at what you want, i.e. depth of field, motion perspective.
Great start.
also f32 is will be getting soft from the 'pinhole' effect. as you open the aperture you will find the areas that are in focus will get sharper.