Photoshop, Gimp, Paint Tool Sai would probably work well but if you want to vectorise it you could always use Inkscape, Ponyscape or Illustrator. Photoshop isn't really designed well to vector properly. Good luck.
Spike with Snips and Snails? I think Spike is a really cool character. He's a dragon well apparently but that makes him more interesting as he is one of the main characters in the show. Snips and Snails are stupid mail sterotypes who are complete idiots. All they really do is obsess over somepony like some overreacting fangirl and worship them.
I think Shining Armor has a much more interesting personality to me than Cadance. All I really know about her is that she has a warm heart, she's well a princess and rules the Crystal Empire and she used to be a foal-sitter to Twilight.
I was never too fond of Cadance anyway.
For a boyfriend I would want one who:
has a sense of humor
kind, considerate and caring
accepts who I am
treats others fairly
who would love me forever
we both share some of the same interests, preferably one who loves music as much as I do
I obviously think she's a bit TOO overrated. She even gets more love than the main characters in the show which are probably Rarity and AJ but that doesn't mean I hate her.
The reason why she is loved so much is one, the brony fandom is overreacting to the fact that she just a cartoon pony with a harmless disadvantage and an obession with muffins. Thats basically all we know about her: she lob=ves muffins and her eyes are always derped and also to add that according to her cutiemark she has bubbles so that might give a clue that she has a bubbly somewhat personality.