There's nothing necessarily wrong with wanting to be a certain hero, but it's important to at least clue everyone in ASAP.

I will say that it sounds like you have a bit of a stubborn streak with regard to your hero choice. A little bit of flexibility goes a long way. Try to expand your hero pool a little bit, even if it's just by one hero a week or something.

If you like Drow for her range and damage potential, you might like Keeper of the Light as a support. His Illuminate has crazy range and harass potential, you can stun enemies for 1.5-3 seconds with Mana Leak, etc. Positioning on him is just as important as it is for Drow (since her Ultimate goes away when an enemy is within 400 range). You also have a push + blind ability that grants miss chance once you get your Ultimate on him. So you can still knock back people who get too close, kind of like you can with Drow.

(I learned the game as Drow and now I mainly play KoTL when I support, so this isn't just a random suggestion.)

As far as Ranked, I played my first Ranked match last night (it said the avg MMR was 1.7k), and everyone except one guy was really friendly. I was playing KoTL in lane with Anti-Mage, and the AM was very helpful and supportive over mic and forgiving of mistakes. It wasn't nearly as tryhard as I was expecting. As a disclaimer, I've played about 350 matches (with maybe 250 being bot matches) so I went into Ranked with a decent understanding of basic things like last-hitting, warding, etc.

The best part about Ranked vs. Unranked to me was the picking phase at the beginning. The first team gets 30 seconds to pick their hero, then the other team gets 30 seconds, and so on, so there's plenty of time to discuss who and where you want to be.

Hope this helps a little.