Questions from an amature

First off - awesome forum. Almost too much information to absorb...

Until recently, when I have a drink, it's a stout beer. However, at 36 the beer seems to expand the gut a more than it did at 25 so I thought I'd try whiskey again. I haven't had whiskey in about 15 years and my memories of it were not fond - but I remember disliking scotch the least, so yesterday I purchased 2 bottles of scotch. Glenfiddich 12 and a Glenfiddich 30. I immediately opened the 12 and was blown away at how much I enjoyed it! (can't wait for another glass tonight, armed with the info I have gained here)

My questions:
1:Reading the forum I have heard several suggestions on scotch brands. Not too many on the Glenfiddich though. I dropped $40 on the 12 and an embarrassing amount on the 30. Have I made a mistake with this brand? I love the scotch, but I am so curious of how much better the other brands are.
2: I cut the drink 2:1 with water (tap) and added 2 cubes of ice that also watered it down a bit. Is this a good method for getting the best experience with scotch, and does tap water make a difference?
3: and last - Should I keep this bottle of 30 or gift it and buy a different brand? I'd really love to hear that I haven't bought bad scotch

Ok, I'm off for my second round of the 12 (still using a wide mouthed glass) but I will remedy that on my next trip to the liqueur store.