If you put furigana on all the words you don’t know before you take the time to study them, I find that it tends to make people a little lazy as they’re drawn more towards the furigana when reading, rather than just trying to read the kanji itself.
I thought the same thing, and so I didn't write any furigana in my book, just tried to remember the kanji. However, my teacher told us to write furigana for any kanji we didn't know, so I tried it and surprisingly it did help me learn! Maybe I'm just good at looking at the kanji first. I guess if you write the furigana small enough so it takes some work to read it, that would work good. If you don't know the kanji well enough to remember the readingwithin a second or two, then you can go ahead and look at the furigana because you probably won't remember no matter how long you stare at it... and if you go over it enough times, you'll learn the kanji.
At least that worked for me...
Just so you know, I'm not offended at all by your use of 俺. However, that's only because I'm not Japanese. It's like saying the F-word to a Japanese person... even if they know the meaning, they don't really feel its effect.
Anyway, one thing strange I noticed about my language school is that although they teach how you're supposed to talk to your teachers and people you don't know well, they don't enforce it at all! I was so surprised to hear students talking to their teachers using the informal form. I just commented on your use of 俺 so you would realize and perhaps practice speaking formally, which is normal when addressing a group.
And, of course, if you really do use 俺 when talking to people you don't know, you should definately work on that... Even if you use it with Japanese friends, if it doesn't really fit your personality type/position in the relationship, it could kinda rub them the wrong way.
I started reading a manga that had lots of yakuza-style talking in it, and so I started to say 俺 without really realizing it. All my friends said "Ug, that totally doesn't sound like you! I don't like it when you use 俺, it just doesn't fit." Lucky for me, my friends actually said something instead of just pushing me away B)