Welcome to the forums!
I am sorry, but no -- no easy way out, I am afraid. But then again, whoever said that video editing was meant to be easy???
The only things that you can set to affect a whole project in the time timeline are set in File > Preferences > Edit. You can choose a default transition, and also set the default times that images remain on screen in a slideshow, or how long transitions last. You can also set how long audio fade ins and fade outs last. But that's just about it, I am afraid.