'ontroerend mooi en klein': 'ontroerend' (moving - I like your translation!) is an adverb, not an adjective here. Also, 'nice' is somewhat weak to translate 'mooi' here. I would say 'beautiful'.
My suggestion would be something like 'movingly beautiful and tiny'.
However, this doesn't sound as nice, by far, as the original (too bulky) so maybe a less literal alternative is needed to capture the -almost- poetry.
For the last line, I would replace 'we are' with 'we feel'.
I definitely like your 'movingly' better...
My comment wasa a bit confusing, I meant that your original tranlation sounds much nicer than my suggestion but doesn't quite capture the literal meaning of the Dutch text.
I think 'movingly beautiful and tiny' does capture the literal meaning - but then the 'fragility' of the Dutch sentence is lost... I think you may have to choose between a literal translation and one that captures the fragile, special, miracle-like feeling of what the text is trying to convey...