Deleted

I gave up this one, but please could you post the solution here after it is ended? Thank you.

Solution:

Part 1

1. SWIM(Q1) without i(Q2:EYE) = SWM
2. SWM + KUZCO(Q3) = SWMKUZCO
3. TREE(Q4) + LAST OF US(Q5) = 3 last of "SWMKUZCO" = ZCO
4. SWMKUZCO - ZCO = SWMKU(Q6)

"sUpEr!" gives the capitalization hint => sWmKu leads to Part 2

Part 2

1. Nicholas follows the co-ordinates outside, where a piece of paper hangs from the carrot nose of a handsome snowman. The note reads:

   Perhaps if you didn't make us work 7 days a week in the months running up to Christmas you would still have your precious blueprints. Working for your corporation is hell!

"The co-ordinates outside" hints that next clue isn't within the giveaway, "Working for your corporation" is another hint, so check the past giveaway with relative words "Corporate Lifestyle Simulator" and you'll be lead here
PS: "corporation" is emphasized when you look at the source code.

2. The description gives "DDBLpT7U" and hence another ITH puzzle.

Part 3

1. Q2 is trivial from Q1 and go to another giveaway.
2. From the caption of giveaway's image, it shows "v" -> ? -> "v".
3. But from Q2, "v" -> "w", and n -> n+2. So "vW6h2" -> "wV8?4", keeps the capitalization.
4. You're asked to bruteforce to get ? = r.
   PS: 'h=r' is given from the source code of Corporate Lifestyle Simulator giveaway.
5. And you are here.
   (to be continued)

Part 4

1. Actually, there is nothing here as ylil said.
2. So, back to the discussion and look at the image closely.
3. http://i.imgur.com/Ggqo6s3.jpg
4. We have done our final part.

Back to Part 3

1. The caption of final part gives the Part 3 ITH Q1 answer.
2. Complete the puzzle and gets

   And there he has found something, finally! Hidden in the back of the stable behind the reindeer's reins, another note. The co-ordinates lead him back to the Workshop, strangely. Has the blueprints been there all along? Nicholas scratches Prancer behind her ear as he leaves, getting a pleased whinny in return. She'd always been his favourite. He trudges through the snow and into the Workshop, taking off his boots as he enters.

3. The italic (bold here) alphabets gives the last giveaway.

I think that's all. Since ylil is busy, so I think I may do him some favor. Hope he no mind. :)

wow after reading the entire solution I don't feel bad giving up in part 1

Same tradition in Germany ;)