Why are haloalkanes more reactive towards nucleophilic substitution than haloarenes?

Identify A and B in the following reactions:

Identify $\mathrm{C}$ in the following reaction:

Complete the following:

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3+{\mathrm{Cl}}_2\underset{\mathrm{Sunlight}}{\stackrel{383 \mathrm{K}}{⟶}}$

Complete the following:

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_2{\mathrm{CH}}_3+{\mathrm{Cl}}_2\underset{\mathrm{Sunlight}}{\stackrel{383 \mathrm{K}}{⟶}}$

Complete the following:

Use Markovnikov's rule to predict the products of the following reaction:

$\mathrm{HCl}$ with ${\mathrm{CH}}_3\mathrm{CCl}={\mathrm{CH}}_2$

Use Markovnikov's rule to predict the products of the following reaction:

$\mathrm{HCl}$ with ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{C}{\left({\mathrm{CH}}_3\right)}_2$

Write the structural formulae of various isomers of ${\mathrm{C}}_7{\mathrm{H}}_7\mathrm{Cl}$ containing benzene ring. Which out of these has weakest $\mathrm{C}-\mathrm{Cl}$ bond?