Alright fa/tg/uys, I have a few questions for you from a prospective, soon-to-be 40k player.

Since this will be my first time getting into it I'm likely going to end up running Space Marines. Now comes the first question: Blood Angels, or Dark Angels? Pros and cons of either? Which would typically be more efficient all-around?

Now the second question: I know rules state that those respective chapters must be painted in certain ways, but would it be too far fetched/would it make too many other players pissy if I fluffed my marines as a successor chapter and painted them to my liking?

Pic related, as I love the Death Company miniatures.