Pandy yah my event sheets tend to look over complicated (I get that a lot). I'm also lazy with not commenting my code very well. Anyway you have to keep in mind that sometimes the simplest solution is not the best (seriously). It might seem like its really easy to just associate an object and have the host create it but you wind up losing flexibility in the process. I create functions for every (and I mean EVERYTHING). From spawning sprites to setting attributes to moving players object to fire projectiles to you name it (EVERYTHING). Nothing happens in my code that isn't called from a function. By doing this I can and do sync every action across all peers with functions no matter who initiates the function. But keeping to what Ashley said some functions are only ever called by the host depending if they are game state events like a point was scored or a hit was registered. IE the peer may signal that he fired a shot and from where but after the shot is fired, only the host is allowed to determine if it made a hit and will call a function on all peers to let them know a hit was made.
Anyway with all that said I cant really help you with what do when you sync objects as I don't code that way. What I would try to do is reduce more of your code to small functions (spawning sprites, destroying sprites, setting text.. etc) and call them on both devices simultaneously as in the example. It will take some time to get used to but you wind having the control your looking for.
To give proof of concept (and provide more complicated code) here is multiplayer platform example that uses nothing but functions. There is some fancy stuff in there that persists functions related to movement to reduce network overhead and lag (you will notice my object have almost not lag) but you will get the idea of how I use functions for everything.
[attachment=0:1fw37z5i][/attachment:1fw37z5i]
Edit: For got to mention you will need the moveto plugin by rex to use it. I assume most people have that plugin by now
Same as before just open 2 browser windows enter the room name and player name in each and click connect. once both players are in use the arrow keys to move them around. (supports only 2 players per room or it will break)