Best way to store and back up data on Mac (retina)?

Ok so I bought the 13 inch retina macbook pro (This is my very first mac btw, so I am still trying to get used to basic functions though it's getting there..) and I've researched it a bit but I have some issues on figuring out how I best should store my data.

1. Is Time Machine not the best way to back up data? As it will delete the oldest data once the hardrive used is full?

but on the other hand, backing things up manually will take a lot of pain and effort (Choosing the new files that haven't been transferred, accidentally copying a file you actually already put in your back up disk thus taking additional unnecessary space,etc) ...right?

or is there a better way to do this?

2. I want to have all media (music, photos, videos, anything except apps) on an external hard drive but I don't want to have to keep transferring it from iphotos or anything else to my external hard drive...

Is there a way to do this a smarter way? It would be best if I could put everything directly to my harddrive instead of having to import thru iphotos (thus taking up space on my internal SSD first) THEN deleting it from iphotos :/

As of now I am trying do configure this network storage system (called SeaGate GoFlex Home if anyone is interested) but I am wondering if this is really a reliable way to keep my stuff... I plan on putting music, photos and videos on there..along with word documents

Is there a way to configure the mac to automatically download stuff to my external network drive instead of saving it on my SSD?

Thanks in advance for any help /opinions 🙂