Get someone who has a basic grasp of grammar to proof-read your posts.

As an example : “Sometime your not able prevent it”, “deliverable’s” — none of the others has apostrophes but that does.

Reviewing the concept, the idea of scope creep suggests that you fix your scope. If you are defining a fixed scope and someone brings additional features to the table then there are simple questions :

“What value is there in the additional features?”

“Can MVP launch without it?”

Remember that you will be adding to the product, preferably very soon after the MVP drop, so you can discuss if it can wait for the next code drop.