Shinra's strength in the manga is quite significant. He's able to overcome various challenges and opponents with his skills and determination. His power keeps evolving throughout the story.
Tamaki remains alive throughout the manga. The plot doesn't involve his death. Maybe you got some wrong information or confused it with another character.
It depends on the specific manga. Sometimes the story progresses quickly, but in other cases, it might take its time to build up the plot and characters.
Shinra stands no chance against Goku. Goku has gone through countless battles and has mastered powerful techniques. His strength and experience give him a huge advantage.
Many Tamaki fanfics are centered around his leadership in the Host Club. Writers might explore how he manages the club, how he comes up with new ideas for events, and how he deals with the different personalities within the club. It's interesting to see how his leadership style evolves in different fan-created scenarios.