Hi!
I would say it can make your driving experience different because you gain an understanding of fundamental traffic regulations and driving rules. It will also aid you with judgement of other vehicle's positioning. I'm still doing my driving lessons and got my third practical test booked this July (I failed the other two practical tests) so I can't exactly give a best response here.
Generally, this is subjective to each individual. I sometimes do speed in ETS2 or ATS but most of the time, I do follow traffic rules regardless. However, I do not always think it might be possible for bad habits from a simulator to pass onto driving in real life. As you gain experience in driving, it will eventually come to you naturally to avoid these bad habits so I wouldn't be too concerned about this.
Regarding this, I wouldn't worry about this as instructors do not expect you to drive 100% perfectly. I can agree people in TMP can be quite toxic when it comes to slow vehicles but you shouldn't worry about other people's driving because their actions and behaviours will come with consequences. I myself sometimes respect speed limits and the amount of drivers honking or making a close pass is abysmal but sadly you can't change their attitude.
I hope this helps