why did hashem create non kosher animals, was it to tempt us and see if we would control ourselves?
That is one reason, sure; in general, Hashem gave us rules of what to do and not to do, in order to refine us (Bereishis Rabbah 44:1).
But aside from that, the various non-kosher animals have their roles to play in the ecosystem - as predators, scavengers, etc. Also, some of them are also useful to us in capacities other than food: consider horses, camels, etc.
The Gemara in Eruvin says that both the cat and the ant (which are non-kosher animals) exists in order for us to learn from their character traits.
If there are no non-kosher animals, you can't get reward for not eating them.
maybe to get a bigger reward for making the right choice and eat kosher
The cycle; blank eats blank and blank which eats blank...
There is also a mitvah to not eat it.
Non-Jews have the right to eat as well, so why wouldn't God create animals for them to eat.
Speculation here. As pets? I guess creating humans through evolution leave tons of side products.
I surely am glad cute kittens are not kosher.