Is a Leash a Must Have Even for Shih-tzu Dogs?

My family recently bought a shih-tzu dog. All cuddly and very tamed, our shih-tzu dog is allowed to roam around the house unguarded. This is despite the presence of two kids who both loved to play with our dog. Reading your article though on dog leash, i got the impression that having a dog leash is a must have. Here are just a few of my questions related to the topic:

1. Is a dog leash a requirement even for the most tamed dog like a shih-tzu?
2. Is a dog leash training effective to ensure dog obedience? Should this be part of dog training?
3. Are there available flexi dog leashes in the market?
4. Is running dog leash not dangerous to a dog, i.e. would this not cause injury to the dog?
5.As a dog leash is used to lead or hold a dog in check, is this not a form of dog control which could be similar to placing a dog in a dog cage? Will this not increase dog aggression? Or will this be an effective thing to controlling dog aggression?

Controlling Dog Aggression

The death of the 4-year old daughter of ‘Ax Men’ star Jesse Browning is indeed very unfortunate especially so that it was their family dog, a Rottweiler, which caused the tragedy. http://www.msnbc.msn.com/id/35650849/ns/entertainment-reality_tv

This once again brought to my consciousness my fear for dogs even pet dogs. As a mother and as a newbie in dog care, I have just a few questions which I hope you guys could help me be enlightened:

1) Is there really such a thing as dog aggression training? Does it really help in controlling dog aggression?

2) In training aggressive dog, do we consider the dog breed, and dogs behavior? could these factors help in designing the dog training tools?

3) What household remedies are immediately available as first aid to dog bites?

4) Is there really such a thing as dog behavior problem? Can this contribute to dog aggression?

5)Kindly give me simple tips in training aggressive dog and how to house train a dog to reduce anxiety at home.