The body painting thing is a cultural more of the Galadhrim, not the Pernostir (ilin classes). Whilst we know that Tud is up for almost anything, he is trying to be a better ilin and tattooing and even non-permanent body art is just not ilin. So Tud might well think twice about agreeing.
Just to re-iterate that point - the Wood Elves do temporary body paint. No other cultural group within the empire indulges in body art of any sort.
Nym should ask Valarwen, who has probably been painted hundreds (literally - she's seen a lot of action) of times before and for whom temporary body art is normal, even expected. FG and TL may also be slightly interested; FG likes magic (and Nae thingy Scillico is magic) and TL likes cultrually important things. Which this is.
Tattooing is entirely associated with the Aerdy. High class Aerdy women tattoo their live's stories on their bodies - it's part of their identity (ie it makes it impossible to keep them as slaves without it being obvious who they are). Tyralandi would almost certainly be interested in having hers updated and Erlini, having been awoken to her cultural heritage by Tyralandi, might well be interested as well. Aerdy menfolk are also covered in tattoos - and the Imperial experience of Aerdy men is not nice. Piercings are also a widespread Aerdy affectation.
Please bear in mind that the cultural gap between the Empire's peoples and the Aerdy is much much greater than it is between the disparate people of the Empire. Certainly the human population of the Empire are not used to seeing Elves amongst them, but they do have a shared history of mutual sufferring, military inter-dependance and eventual liberation. The Aerdy are quite often the bogeymen in the childhood stories of a lot the Empire. In Ulria and Perrenland, when the common people see Tyrlandi and Erlini (or anyone with a tattoo or inexplicable monkey's tail) they stop and point. In urban areas they jeer and spit. If the ilin were not there they may well get stoned or lynched.
In a world of 'them' and 'us' the Aerdy are 'them'. And peircing and tattoos are Aerdy.
The Nae Larach Scillico list is cultural artefact, not a utility spell list.