Nope, all points definitely valid from both you and princeandprez. And I am a marketing major so those thoughts are all things I have considered. My idea was to grab a lot of the market during the playoffs of the bay area baseball teams right now - a while makings shirts of teams I love. You're definitely right about switching markets so i do need to be careful about that. While I don't necessarily want to be cartoony, I definitely don't mind the style of Johnny Cupcakes (though not as "cupcake" as his brand - a little more edgy. I'm looking to find a niche between his style and your basic streetwear style as well. So maybe there is a middle ground there for me.
Good thing here is I own a professional screen printing company so I can quickly shift gears according to how I feel the designs are being perceived - hopefully I can use that to my advantage.
I'm a marketing major as well that's dope how you have that screen printing company man, definitely a huge up. It would be good if you could really set yourself in the niche you're looking for. Hope it pans out, interested to see how your work will grow.