All of the replies explaining strats are correct. I did not see the one question you had about skipping cut scene. AFAIK skipping cutscenes is not a no-no in game or in the speed community.
The thing that is a no-no and the reason why the teleport to base command was changed is because a specific group of speed runners used a dev command to teleport directly into any map they wanted to.
The Veractity speed team members were not ones who used this "cheat." Yes, the team members were optimized. They thoroughly researched builds, and the different TFs, Trials extensively in order to get those times.
Members of Veracity were also very welcoming to teaching members of the community not only how to run speeds, but also how to run content in general.
If would like to see vids of speed runs, or you need recommendations for great SGs that teach and run content on Torchbearer, you can reach out to me on Discord @Sellefane#6019 or PM me here.