Thanks for fixing that last one. So, today I had a little more time to give it a try. Here's my solution for the third puzzle (spoiler alert!) http://goo.gl/q8udM
You asked "how hard were they?". I used Adobe Illustrator to manipulate the tetrominoes easily (I used a keyboard shortcut to rotate 90 degrees using an Illustrator action). Now, since I saved my progress in several files, I can see how long it took me to solve each puzzle. The first one took me less than 5 minutes, the second one took me about 12 minutes and the last one took me about 39 minutes. Yeap, the last one was tricky.