I read this board a lot and only post occasionally. I find myself agreeing with most of the advice on here, but sometimes there are things that I don't entirely get. Here's one that confuses me that maybe you can shed some light on.
I understand why you can't throw your own shower as it's supposed to be "showering with gifts" and that's totally innapropriate and greedy to plan for yourself.
However I don't understand why it's bad etiquette to plan your own engagement party. I didn't have one so I can't say from personal experience, but I've never seen engagement parties as a gift-giving occasion. The ones I've attended haven't involved gifts beyond a bottle of wine or a dip to pass around. I've seen justification used that it's impolite to throw parties for yourself and that would make sense to me except isn't that what a wedding is? What makes it okay to throw a wedding for yourself, but not an engagement party?