If these "examiners" and "exams" were a part of a regulator approved training program for a PPL course
I really doubt it
A qualified pilot receiving sim training [hopefully] already understands the criticality of a minor screw up, resulting in a crash - sims cannot train that, and actually defeat that learning.
I would love to say that I am completely aware of that but I don't know if I can, based on my sim experience only. Reading reports of crashes/incidents really shows you how small details can easily cause crashes. None of my flights online led to a crash but in the sim, there are tons of factors that are irrelevant but aren't IRL (icing for e.g.).
Your greatest real piloting success going forward from here will be to not sim at all, unless the training course tells you to. Enroll in ground school and learn exactly as the course leads you - don't mention your simming at all! Then start your training at a flying school, and learn as taught - don't mention your simming at all!
So would someone that has never heard of airplanes before learn quicker than someone who has thousands of hours of sim behind? Even if that simmer learnt some great things in its virtual career? When you're simming there are tons of rumours about how you should fly an airplane. Once I met someone convinced that flaring was made by trimming only and not using the yoke except to stay in the centerline. This guy might probably take a bit longer to get his first solo.. (unless I am the one completely wrong...)
I know that training is always the first priority. If my instructor teaches me something I'll definitely not come in and say hey that's not what I learnt in the sim but if the training matches what I learnt in the past then it can only be advantageous for me couldn't it?
I can confirm all the above reserves from my own experience as a student pilot. Having "flown" thousands of hours on MSFS, I drove more than one instructor to despair by looking at the instruments all the while.
Heard it multiple times. I'll definitely try to not make that mistake. In the sim, looking outside is quite boring as you always need to move your camera so you tend to rely more on instruments.
And forget about de-icing, you are many hours of flying from the need.
My deicing question was more for curiosity than any other thing 
NB are you going to learn at EBGB Grimbergen? If so, your time might be better spent at brushing up your Dutch
I am really bad at dutch. 
I thought about going there, even visited the club but went for the Roger Sommer aeroclub instead because it's cheaper and a friend of mine has also started his training here so I will be able to see his flights from the backseat which I think is a great learning experience as you can learn from his mistakes in addition to your own mistakes and therefore improve 2 times faster. 