Just to make it clear - I think that the puzzles that you designed are very good! It's not trivial to make such a level that it feels natural but has only one way to solve it (which is not obvious from the get go). It's just the fact that if you make them one-by-one it starts to become overwhelming. Players need some room to breathe (I believe Zack talked about it in one of the episodes... maybe the one about pacing? I'm not sure).
I also understand what you say about the tweaks. On one hand - I'm on your girlfriend's side on this one. Dropping by 2 to be lifted by 4 was not intuitive and felt more like an issue than a deliberate feature. On the other hand - yes. Changing this rule would require you to redesign your levels. I guess that's a bit of a drawback of puzzle games - level design is tightly coupled to game mechanics. That being said - maybe correct process of developing such a game is to get extensive (and I mean EXTENSIVE) feedback and playtests on core game mechanics (is it fun to begin with) before you design more than a handful of levels? I don't know, just thinking out loud.
And don't be sorry for making me feel dumb. This is something I need to live with :D (By saying that I wanted to emphasize that with puzzle games you typically aim to evoke feeling of accomplishment... yet, paradoxically, if puzzle is challenging you can evoke frustration instead. On the other hand you can evoke boredom if there is little to no challenge... I guess it's a tough nut to crack! And you did amazing job, especially that the most feedback for you game was related to mechanics or visuals rather than level design!)
Anyways - to answer your questions.
Yes, I did use the help button and I found it helpful. I liked that the help was a clue rather than a level walkthrough.
I did not click the "watch tutorial" button, sorry :D Mostly because I felt like clicking the second button and getting 1 life back was faster.