I'm planning to visit the following places in June:

Kuala lumpur
Cameron highlands
George town
Perhentian
Medan (sumatra orangutans)

I arrive and depart from KL. Any recommendations to move from one place to the other, and in which order?
Going to Cameron Highlands seems like a pain in the ass since the bus is 3 to 4h are there better alternatives?
Better alternatives to Perhentian to dive? (not in Borneo)
Are Singapore or Melaka worth visiting?
Any other places worth visiting?
All tips welcome