If you use an APC prop, it won't fit the stock prop adapter. Stock prop adapter shaft is 8mm and APC prop holes are 6mm. Whether or not you use a spinner is totally cosmetic. Hyperion has an adapter that will fit the stock motor shaft (5mm) and will fit an APC prop (6mm), plus the "extra long" version will have enough room to fit a spinner of your choice (Hyperion also makes some nice lightweight spinners). The stock spinner will not work with the Hyperion prop adapter. Here's the adapter I use...
Depending on the size of the spinner you use or if you don't use one at all, you may be able to use the regular length adapter instead of the "extra long". Hope that helps.
BTW...this is a quote directly from E Flite's website regarding the Carbon Z Yak 54...
Due to the high RPMs of this aircraft it is extremely important that you use a balanced propeller. Balancing the propeller as well as the hub is equally important in this situation. Failure to use a balanced propeller and hub will result in premature fatigue and possible failure of the aircraft components."