Dear Yong Peng,

> I am in the process of preparing the next section of Buddheniyaa
> Vatthu, and I am stuck with the word vandeyya.m, which I understand,
> with limited knowledge, as the passive 1st person singular optative
> of vandati, meaning "I should be honored".

Why do you think it's passive? -eyya.m is an ordinary active 1 sg. optative.
http://dhamma.ru/in/palisufi.htm

> yannuunaaha.m tattha gantvaa bhagavato jayamahaabodhi.m vandeyyan'ti
> cintetvaa

Thinking: "What if I will go and honour ..."

metta, Dmytro