Yet another birthday thing... [solutions posted in 1st comment]

It'sIt was my birthday! And only 2 more days, then since yesterday my Steam existence is 2 years old! I haven't been here for that long, but still... time to get some celebratory trains going! :D

Small group & Whitelist GA
Small train for everybody (Lv 0-1+)

To get to the bigger, better and faster (?) train, you'll have to solve one of these...

1. Numbers, for those who miss them by now fixed Q4, try again if that's where you were stuck
2. Something with text hints at the end of this post and in the puzzle
3. More text new hints
4. Videos! pretty much the easiest one
5. Uh, text again more hints added

All lead to different stations, but all are on the same route. You may get off at any point (maybe find a hidden pathway?). Levels 1-4+ may enter, open till Monday, August 17, 10 PM GMT+2
I hope everything works, let me know if something seems off. All puzzles should be pretty easy, didn't have time for anything elaborate; train includes some unbundled games, so have a look ;)

And now, time for cake! :3

(thanks for all the birthday wishes :D)

Some (by now probably outdated) statistics for you about the main train with the puzzles (including hidden GAs):

Total number of GAs: 15 (11 bundled, 4 unbundled)
Average entries per GA: 15.8 (3 with less than 5 entries, one of them unbundled)
Total points to spend: 240
Average solvers per puzzle: 25.8

Updated hint for P2:
Think about what the description is, and what it's usually accompanied by when you see it somehwere - that's what I'm after for the others (the puzzle is really just about finding out what they are). Also, if you've solved one of the other puzzles and have been to the train, you've come across one of the answers (not the question though) - from there, it's only a few clicks to 2 more answers ;).
And if that's the last puzzle you haven't solved yet, don't forget there's always bruteforcing if you can't figure it out ;)