Would the study plan work for an engineer as well, or any other majors for that matter?
I don't see why not. I'd be interested to hear what people say.
EBOOKS / PDFS
As far as the digital storage of as many texts as possible, there is no downside that I can see.
NOTETAKING APPS
Notetaking software like VoodooPad is more of a personal preference. I still use Evernote for some stuff, and I tried really hard to make it my main notetaking app. I think if I were in a different line of work, I could have done it. Ultimately, though, it failed to meet my needs.
EREADERS / TABLETS
I don't think anyone would complain about having all of their books in the palm of their hand. However, it really works best for linear reading (some humanities) and not so much for non-linear reading (some hard sciences). In other words, you can't flip back and forth through an ebook as easily as you can with paper. You can only view one page at a time, so footnotes, endnotes, glossaries, and other things become a pain. I have the Kindle DX, so I can get two pages at once. Maybe, if you had a 27"iMac you could get three pages at once. It's a small price to pay (in my opinion) for the convenience.
HANDWRITTEN NOTES
This is personal preference. It is obviously less efficient than just typing everything in directly. But, I think the learning process for every endeavor can benefit from multiple strategies, so it can't hurt either. For me, the process of recording, re-writing, re-interpreting, re-viewing, and re-organizing help me to internalize ideas and information. I really despise cramming, because it cheats you out of a chance to really learn the information, and it is painful. It takes more discipline to revisit material, but is far more effective over the long term to come back to it again and again from different perspectives. That sounds like something that would work in any discipline, right?
ORGANIZATION
The method I use is a modified version of Noguchi Yukio's famous (in Japan) organizational system for filing papers. The guy didn't have a terribly clear system for computers (at least in the books I read), so I had to tinker with it. I've been using it (the system I mentioned earlier) for about a decade now, and it works great for me. I know some people who cannot stand the thought of dumping everything into one folder and really want to organize things into endless hierarchies of folders. I can see the merits of that, but I tried that for a while when I ran a small business, and I dreaded all of the filing. Now that I have used my system for a while, I figure that there isn't any reason why it wouldn't work for any field.