Well, lack of icons for manovers is not a bug, but it would be great to have some, don't you think?
I don't know if anyone is working on this right now (probobly not, since you have other and more important issues to deal with). So why not use already made icons (like those used for psionic powers)?
I saw some nice images on the Vault, maybe they will do? (Those form World of Worcraft are very good, and already converted for NWN).