Sure, it is always important for me when choosing a location for my server, I think my websites will load faster for visitors if my websites are putting at their country. Thats why I prefer choosing US loaction.
Well, it's pretty important because of the latency. It increases as the distance from the server location increases. Also, the google ranking and loading speed depend on the server location. So yeah, better choose one wisely.
It depends what you are running on the server. In general, you should have your content stored on servers as close to your end users as possible. It's one of the factors how fast your content will be available to your users; you don't want them to wait. Get a few IPs from your users and test Traceroute or MTR to see which locations will be the most suitable to your needs. Experienced providers will be able to recommend the location if you tell them your needs as they know their routing and network capacity.