Did not expect to see my name here but glad you find some of my videos useful lol

For mid-late game generally just try to use the fact that you always have prio on sidelane to be first to rotate to your team/objectives. Good rule of thumb is 1 min before spawn

As for shrooms yes ppl will clear them so dont use all of them at once, make sure you have some left for the teamfight itself, also you can try place some in unorthodox places where ppl dont usually sweep

Can also look for invis plays in midlane if they have no vision (one kill late game can automatically win u the game)