Should I get the Xperia Z3 Cruzerlite or Love Mei Case?

Hey guys, I am going to buy a Xperia Z3 (My very first smartphone :O) sometime this weekend and had a couple of questions.

1. I have heard about some sort of overheating issues with this phone, especially when shooting 4k videos or heavy gaming. Is there anybody that can respond to this.

2. Depending on the answer to the question above, I was considering between two different kinds of cases. First, should I go with a Cruzerlite Bugdroid Circuit Case/Tempered Glass combo (Not total protection but will have access to magnetic charger port) , or a Love Mei Powerful Bumper (Total protection, but no magnetic charger access and I'm afraid if completely sealing up the phone is a bad idea if the overheating issue is true).

Thank you and fingers cross for my first smartphone.