Changing back to a manual I had to remind myself to press the clutch while putting the car in gear with the engine running. And not just having the brake pedal pressed. But you get used to that quite fast with the awful grinding noise.
Easing it in could in theory lead to a slipping clutch plate which might wear it out sooner. Completely disangaging the clutch without delay seems to be the best to me.
It’s only when you are driving off that you’ll want to ease off and have it slip ever so slightly.
Well, judging fron the foot slamming, you haven’t completely forgotten how to drive a manual. So I’d say you’ll still be able to drive those after getting used to them for a bit.
As for the pedals, it is possible since to hit the brake with the left foot by mistake. Since not all foot wells are designed the same and in my experience the automatic brake pedals usually are quite a bit wider.