When a toddler asks you a question, either it comes out of curiosity or it could be just attention seeking. Whatever is the case, it is always best to feed your child's curiosity and give them undivided attention.
A child is bound to throw a tantrum because who else if not the child. This does not mean the tantrums can not be tamed.
If a child is not playing alone, it does not mean (s)he is an introvert child, there can be other reasons as well.
Children model their parents the most. Develop the listening skill yourself and then help the child to achieve the same.
Discipline teaches your child how to behave and how not to behave in social and routine situations. It also lays the foundation for the kind of adult the child is going to be.
Children do not understand the concept of "stealing" so instead of dealing with this situation using your anger, it is better to sit with your child and make him/her understand why they should not be doing this.
Intolerance is not the same as possessiveness. It might have underlying reasons.
Nail biting is common not only in children but also in adults. It is important to understand the underlying reasons behind this habit.
Knowing the interest of your child will help you guide your child better.