Will external doors be made stronger so you can't just open them by punching the door?

One of those great game dev quirks: technically melee is doing physical damage. So over time, it will do enough to open doors. Short, midterm, we're going to be bringing in, hopefully alongside engineering, the concept of armor having minimum thresholds of damage, like damage numbers. So punching would just never exceed that threshold to allow you to open doors. Longer term, Maelstrom does this. Out of the box, it's functional now in Squadron. Your punch doesn't do enough kinetic energy for the system to even care about, so you'll never be able to break it like that. And as the interim, until that comes into the PU, engineering will hopefully bring the lightweight version of that that approximates the same outcome.