This is going to be difficult to formulate without revealing too much, but I'll try:
Is the first 5-letter word for the thematic occasion an adjective or a noun?
Am I right in thinking the 2,7 work is a very early one, and the 3,5 one pretty late?
The real problem of course is how they are interspersed --- apparently quite randomly. Even so, a few of my 31 letters must be wrong, I think. it would help a lot if someone could answer those two little qq first!