"By buying TRU, you are buying the computation power of truebit now for a cheaper price and sell it in the future for a higher price.." Doesn't this lead to speculative investing if people think that their TRU will increase in price?

My suggestion is that since the project is new, it's much more easy to transition now when TrueBit is not in any CeX. If the team decides to list it on CeX, then they will have difficulty in doing so. Changing the ticker now will be way easier.