can i use heavy line in my small baitcasting reel??

I just bought a Shimano Citica 200 E and put it on a Bionic Blade Med. action pole from Bass Pro Shops. 14 lb is the highest recomended by Shimano. I see guys on TV using 50, 60 lb test with reels that look similar to mine. 1) Please explain what is going on here? 2) Can I use these higher test lines with this reel without consiquence? 3) What kind of line do you suggest for long casts with med sized lures and baits? 4) What kind of leader arrangement do you liked? Thanks--I am new to this type of reel and fishing.