Network tool for troubleshooting & reporting

sometimes i do computer network survey or network troubleshooting for some small companies, so i am looking for a simple use network software or tool that help me to do the following:

(1) show me a quick network layout.and suggest to any change in the network design.
(2) show me a network traffic report such as:
(a)any bottleneck.
(b)most traffic generate network equipment on the network.
(c)network cables utilization.
(3) inventory to all network equipments on the network