Cakeday II - The real one [ENDED...BUT ADDED ANYWAY A HINT] :D

Good evening my dear adventurers, some of you might remember me, some of you might remember my puzzles, some of you might not remember...
ehrm sorry this was the script of the last thread...where the hell is it, oh darn, here you are!
As I was saying, come here my dear adventurers, and tell me: do ye dare to undertake the overwhelming and full of perils journey that I, the evil puzzler, have set just for you? Are you ready to crack your brain like an egg and cry like a baby among tricks and riddles? Just let me tell ye something before ye answer: do you know what awaits the ones that will prove their sharp mind and their brave hearts, passing all my tests? Oh my, my, you really didn't know of the 101 giveaways that lie there, at the end of my trials?
Well, now you know, go and prove yourself to me!
Just choose one of the five paths, and remember, the higher the number the harder the trial! huehuehuehuehuehuehuehuehuehuehuehuehue! >:3

1. PUZZLE

2. PUZZLE

3. PUZZLE

4. PUZZLE

5. PUZZLE

Now just a little serious footnote:
Two years ago circa I've discovered this community and one of its characteristics that particularly astonished me is the activity in the puzzle section...when I first landed there I was totally disoriented and I understood nothing, but then I’ve gradually learnt to solve puzzles and even create them! I remember the braincrackers created by Nordhbane, Fnord, Mykalie, Ercalote, Keohookalani, JonothanKalo (that became an owly), Sexy(or evil)budgie, Dingbat, alamarjan, silentguy, ozo2003, Adelion, m3rc, Lugum, SuicidalSnowflake, Fnord, fiftykyu, Gracee, jbondguy007, jeffhowe, kerros, mecorx, mushclone, nellyneko, iflirtwithanyone, Oppenh4imer, Ronix, Student123, Tewam (YES), Revilheart, malabagaa, mecorx, treeB, wc terror, chronicdiscord, yukulele, zelghadis (whose guide also helped me and many other puzzlers), theZooZ, Server51(that also created gameofswords) and many, many, many others that I can't recall atm. What I mean to do is not simply putting down a list of puzzlers, but expressing my gratitude for this awesome community that gave me a lot and that (I hope) I'm contributing to a little. This has been an awesome journey up to now and I hope it will always go on like this. It doesn't matter if you are a puzzler, a solver, a lurker, a leecher, a charitable loser, a greedy winner, an admin, a newbie, CG, a super user, a touhouer, a bundler, a flamer, a troll, or a simple, average, normal user...Steamgifts will always give you a lot and feel a little like home <3 THANK YOU EVERYBODEEEY :’-)

And for the practical footnotes:
Of course, don't discuss the solution or share hints, in order not to waste my time spent on the puzzle and the fun of solvers (especially don’t share ANYTHING from what you find at the end of the puzzles)
There's no level restriction and no SGtools
There are 101 different GAs, some with multiple copies, some crappy, some good, some very good, some awesome (each of the puzzles has a different reward, and the toughest the puzzle the better the prize)
You'll have 14 days, meaning that the clock stops on January, 25 at midnight CET

Clues and hints

Hint#1
Many of you are concerned about how many people solved every puzzle. I can keep no track of who's solved each puzzle but thanks to this you, like me, will be able to know who has solved all of the 5 puzzles (and I assure you that I've kept the best for the final reward, or as the latins said, dulcis in fundo).
Also I cannot keep track of precise data, but according to entries and comments inside the trains I can tell you that, the order from the most to the least solved is:
1 - 2 - 4 - 3 - 5
Hint#2
Puzzles 1 and 2 are quite easy, for number 3 I often suggested the ones of you who asked me hints to look at it from any perspective, but I forgot to mention that by perspective I meant contrast, for puzzle 4 I've already dropped a huge hint in the comment section and about puzzle 5 someone of you asked me if it is about frequency, well it is not about frequency, but frequency is really a huge indicator of what you should be looking for.
Hint#3
Puzzle 3 and puzzle 5 have the same encryption method, which is a really simple one (namely if you've solved the easier questions of puzzle 4 you surely know it). Remember also that I use to drop tiny sneaky hints in comments.
Hint#4
The words in puzzle 5 are separated by commas and space for the sake of readability but I could write it like this: sophisticatedinstallationalthougheconomicsownershipactionaircraftcooperativeministerallowanceheroicincludeconfigurationunquestionableinflammationmathematicaldevelopedcomponentbreakthroughobliged
The only thing that must not be modified in order not to corrupt the solution is their order.
Hint#5
Puzzle 4: (just a piece of advice) when I first encountered the language of Q7, I've looked for and found a browser that could search symbols.
Puzzle 3: if you followed my previous hint you've probably found 5 "elements", each to be decoded into a single character. Each one of these elements has 8 "vertices"...does it ring the bell?
Puzzle 5: if you followed my previous hint about frequency you surely noticed the prevalence of two characters. Now, we're talking about decryption, ain't it? So, what do these two characters look like? What's the most obvious graphical association to them?

After-ending clues and hints

Hint#1
I think that for most of you the last one great obstacle it's puzzle 3, well so read my previous hints again but instead of vertices read angles.
Hint#2
For puzzle 4, question 7, this is the comment where I dropped the huge hint. Of course it's huge but it's not obvious, otherwise it would have meant to spoil the solution.