As you said, the words on that site seem to be logically derived, based on known words. In my opinion, they are to be used as a last resort, when no other related word or synonym can be found.
With this in mind, I have a couple of questions.
1. What are your opinions on combining words to make compound words? The poem I'm translating has a nautical sort of theme, and one word I had to scrounge around in order to translate was 'figurehead'. I settled for
lango-nís = 'prow-woman'.
2. Is it okay to 'logically derive' a noun from a verb? Again, as a last resort. I need a word for 'sail' (the noun), but I can only find the verb:
wili-. Could I somehow follow the pattern
linda- (verb, sing) -->
lindë (noun, song)?
Willë would not be an option because it's the past tense form of the noun, but maybe there's some way,
wilë, perhaps, though it doesn't look as nice... Or, I could try another compound word,
rúmëa-cirya (moves-ship) or something similar.