2. What kind of bike should I use?

1. Hermes:
"This question depends on one's riding style. If you are a beginner I recommend starting with a mountain bike with slick tires. Try to convert as many quick releases to allen key bolts, or traditional bolts. I wouldn't worry too much about the bike looking too 'new'(thus theoretically being thief-bait) your bike will look like shit quickly enough without you having to go out of your way to make it look that way. I would also rather opt for a bike that is slightly 'too small' rather than 'too large'. Bike shops tend to fit bikes to people without any understanding of what bike geometry is best for urban riding. A shorter wheelbase (how far apart the wheel are) is much more maneuverable than a longer, more 'normal' one.
If you'd rather use a road bike the plusses are: it's faster, and has more precise steering and control. The cons: it's less comfortable, will probably be a bit more expensive because it won't hold up as well as a mountain bike, and it can't stop quite as fast as a mountain bike.
A 'track' bike's pros: it's the cheapest choice as it has fewer components to buy, and less can break on it or be stolen, it's very light and accelerates quickly, and it can be a fun, flowing, almost spiritual kind of ride. Its cons: it is the least "comfortable" choice, and you have to really learn a whole new riding style to effectively use it in traffic."

2. TONE:
"I personally use a mountain bike with thinner slick Kevlar tires. I'd feel sorry for a bike that couldn't take the abuse I put it through with the hard way I ride and all the stuff I carry. I've cracked two Spin mag wheels (three spoked), and broken god knows how many spokes on conventional wheels. Now I ride with AreoSpoke mag wheels (five spoked). If you are wondering... I like mag wheels because I don't have to true them, the heavy three foot chain can't warp the spokes, and it's much easier to get the chain through the front wheel with mags especially during cold wet weather where normally your fingers would get colder, dirtier, and caught/cut up in conventional spokes. Just so you know I lock my frame and front wheel to whatever (pole, banister, fence, etc.) and have a small little lock through a hole in my quick release lever on my rear wheel which locks down to the chainstay. I've never had a bike stolen yet. By the way I recommend either taping up your frame or wrapping up your frame with old inner tubes. This protects your frame from getting scuffed by whatever, including your own chain, as well as conceals how nice your bike really might be to potential thieves. I don't wrap or tape up my own bike because I like the chipped paint look my chain gives to my bike (it's aluminum so it won't rust), and I also deliberately peal and scrape off any brand name stickers from my bike. This also helps to make the bike less distinguishable from others if you happen to be chased by the cops for something YOU DIDN'T DO"