Evil exists and is therefore evidence for the existence of an all powerful and all good God.

I tend to agree.  I think that if you grant the assumptions made the argument goes through - the problem is spotting the hidden assumptions! 

I'd say "But the Unmoved Mover, as the source of all change," is an instance.  The assumption is that the natural, default state is stasis.  But you don't need anything to extra to make the world change.  With our crude, unaided senses it can seem that nothing much goes on without an external agent.  A glass of water on a table just sits there.  But come back in a week and the water will have evaporated away.   An 'inert' block of metal is a maeltrom of sub-atomic activity.   Nothing is truly static.

Change and motion are the defaults, not stasis.  Aristotle belived a steady force was needed to sustain motion because in common eperience if you stop pushing on something it stops.   There were no ice rinks in ancient Athens for him to skate on!

You are right about the default state being stasis. I hadn't thought of that. Feser's argument implicitly denies that. (Change happens; we never see anything change without something else changing it; we can't have an infinite chain of changers; therefore, there must be an unchanged changer.)

I always approached it with the idea that literally everything has been in motion since the Big Bang. Yes, the BB is a mystery, but so is God, AND the BB is only one mystery. If you choose God, you end up with many mysteries (God, a supernatural world, many supernatural entities, etc.), so use Ockham's Razor and settle for one mystery.

Now, as you pointed out, I can say, "When has there ever been stasis?"