3. You are allowed to have those. A have a question, what is and uber? Sorry, I a noob to those things.
"In German, über is used as a prefix as well as a word in its own right. Both uses indicate a state or action involving increased elevation or quantity in the physical sense, or superiority or excess in the abstract."
A description of 'uber' is above, an uber Pokemon is a Pokemon with highly increased stats, a Pokemon with an ability that Pokemon type does not have (like a Pikachu knowing Wonder Guard), or an unusual attack set.
Basically a hacked Pokemon.