"sometimes" is just 'tenpo la' but actually implicit in the bare forms, which are not meant to be true more than once. In any case, you have the situation backwards apparently, and want 'ona li olin e mi la mi olin e ona kin lon tenpo' or so.
'lon anpa pi sewi suli' "under the big sky" either in front with 'la' or at the end. The spatial prepositions of English (and Spanish) turn out to be 'lon' + one of the physical positions: anpa, noka, insa, poka, monsi, sinpin, luka, lawa, sewi. "I kiss her" is just 'mi uta e ona.' tough the more elaborate 'mi pilin e uta ona kepeken ut mi' has its fans (in romantic fiction, I think).
A verse is 'wan pi toki musi' or maybe 'kipisi pi toki musi', "phrase" works pretty much the same.
tp doesn't do relative clauses or reductions of them well (at all!) so "like dew falling on the grass" has to be a prepositional phrase, i.e. "dew falling on the grass" is a noun phrase and so can't contain 'e' (left over from a long ago sentence parallel to this one) so, something like 'sama telo pi anpa pi tawa kasi anpa' "like water falling to the grass" or, 'sama telo pi kama lon kasi' (I think, but I am tempted to add another 'pi').
'suli ala' does mean "not important". The two faces of 'awen' are hard to distinguish (even with context). "Because/from my not being distant"?
Don't need the 'ni:' since what you are pointing to is already a noun phrase.
I still don't get it "Dark temporal similarity causes plant similarity to turn white." The rest works. Even shifting the 'sama' to the end doesn't help much: "The same night turns the same tree white."
no 'e' with 'kepeken' (ever). could use 'pilin' in place of 'jo'.
The whole 'pi' means "belongs to" thing goes way back and should have died early on, but Pije has perpetuated it. convert to 'jo' if you want to stress possession (which is usually the point) 'jan ante li jo e ona. tenpo pini la uta mi li jo e ona'
"forget x" is 'weka e x tan pilin/lawa' So the noun looks to be 'weka pi tan lawa/pilin'
'luka mi li sike e ona' is straightforward for "My arms are around her"
'pilin' is tricky. Aside from the unfortuante 'pilin pona' and 'pilin ike', we generally get the adjective right and then explain that it is a feeling application rather than, say, an objective one. so 'kon mi li pini ala pilin' , though this is ambiguous because 'pini' is a modal that can suck up 'pilin' as a verb and we get "my soul doesn't stop feeling" So, maybe 'wan' is better for "complete" : 'kon mi li wan ala pilin' 'lon ala' seems a bit extreme.
"this is my disastrous end/ my final disaster", take your pick
Something has to go into 'toki musi pini mi sitelen tawa ona' I guess you mean "this is the last poem I write for her" but I don't see how to do that in one sentence in tp: 'mi sitelen e ni tawa ona. ni li toki musi pini mi sama ni' Or some such.
There are lots of words, but the word lists have not been kept up to date and do not circulate as they should. On the other hand, it encourages you and everybody to make your own and not rely on others.