RE: Second plane--skip one?
It's important to progress beyond the trainer stage -- our buddies are watching, & that ugly old trainer just can't cut it with the flashy 3D & Sport fliers -- right? Besides, you want a new plane -- right?
I've seen this too many times to count -- & I've seen a bunch of broken airplanes and broken hearts.
GO SLOWLY -- you will be a better pilot for doing so. What ever you chose, make sure that it is well within your capability as a pilot, or you will be frustrated, discouraged & fearfull of flying your new Chili-Pepper Aerobat Mk 11. It will fly you -- for a while -- until it goes to the great sandbox in the sky -- and your buddies will be watching that as well.
Can you truly wring your trainer's neck? Good pilots can make a trainer dance like a wonder-bird, & if you struggle with doing so, it is a clue that your ability is still modest. It is easy to do interesting things with aerobatic models, but that doesn't mean that you are a capable aerobatic pilot -- just one that is flying a model that does that stuff easily.
The more that you explore your trainer's real capabilities, the truly better you will be as a pilot. Additionally, the longer you wait to make the "second plane decision", the greater the liklihood that your decision will be well informed and personally relevant.
A very good intermediate step is to hop-up your trainer with a powerfull engine and some simple aerodynamic mods -- like a tail-dragger & no-dihedral wing set-up. That can be a lot of fun to do and to fly, while still developing your skills & letting you gain perspective.