Given that there's so little of it, I've never really given Valarin much thought outside of how it sounds and some of the longish names sounding cool.
http://folk.uib.no/hnohf/valarin.htm
According to the link above, concerning grammar: a plural infix -um- appears to appear in Mâchanâz pl. Mâchanumâz "Authorities, Aratar".
Gando already noted the very limited corpus, and according to the link, this infix might be the only thing that seems somewhat safe to say about Valarin grammar! Concerning syntax (link again), adjectives seemingly follow nouns... if so, now we need thousands more Valarin adjectives and nouns...
... just for starters
