Funny you mention the Friday morning thing, I wasn't sure the problems wasn't my lack of coffee yet!
I think you are probably correct in assuming that the other brewer was thinking of orange blossom honey since I see alot of people using that and few using the blossoms themselves. That said it may not hurt to check with whoever is running the competition just in case, I would just be explicit and tell them blossoms not honey.
I think your recipe sounds good. I don't think it will be too overpowering to have the blossoms and zest/peel in the boil, I have heard of people having problems when adding too much of flowers in the boil and it coming out too earthy and green but that is more of an issue of quantity and may be specific to rose and hibiscus, which is what I've heard it with. I suggest throwing some in the boil to make sure you extract some flavor but I like the idea of throwing a bit more in at whirlpool, you should get more aroma that way. I would avoid over doing though because you can try it after it's done fermenting and decide if you need to add more to the secondary etc. I do recommend making a tea with it to add to the secondary rathern than dry hopping, you will extract more flavor out of the ingredients than you would if you just put it straight in, you could heat and steep the tea stuff rather than boil if you want to keep more of the aromatics. But some of that decision may be better made after you taste it. If you haven't yet I would search for the amounts of blossoms and zest others have used for similar styles to give you a good starting point for how much to use, if you can't find something quite the same you could look at a different style and just bump it up a little to compete with the hops, assuming you aren't on the low end of hops for a pale ale.
I haven't tried them yet, I actually have a beer fermenting that I've used it them for, but bavaria mandarina hops are supposed to have an orange character and might work for you. They are more of an aroma hop but they may work. You could either not add any at the start of the boil but add a lot at 30 minutes and later or you could try using a small amount as a first wort hop and then adding some later.
Please post about your results and quantities as you go or when you are done. I'd be interested to see how this works out!