I am a non-auditory person, I'm not active on CW now, and it's confirmed I suck,
so take my answers with a grain of salt. But it's safe to say I was a "hard learner" when
it came to CW, and then some.
Q1: It's all a matter of opinion, but when I decided to learn back in the old code-required
days, I let the tests be my guide. General and advanced needed 13 WPM, and Extra was 20 WPM.
So when I learned code I went with Farnsworth type weighting, with characters sent at 20WPM
and a spacing of 13WPM. That gave me headroom if I thought I could get to 20.
Your character weights seem really fast to me, but maybe a CW old-timer will add in his opinion.
Q2: Honestly, if you put in 15 minutes a day, even if you're a slow learner you should have the
code down OK at one month, and be pretty solid at 2-3 months. It took me about two months
to get to the point I could confidently know I'd pass an exam with 80% or better accuracy.
Q3: Practice. Practice, practice. Eventually you'll beat your brain into submission. It's the same
as dry firing or anything else. 10-15 minutes a day is actually a lot of training for most things.
DO NOT try to use any shortcuts, mnemonics, or other tricks, just associate the sound
of the character with the character and keep at it. Stuff like "dit-dah-dit-dit, the heLL with it," etc
will mess you up at speed because you're thinking too much. Pick your style though, if you're
going to copy on paper, then just get into a listen-write loop, and if you're going to copy by
ear, work on that. Thankfully there's no exams to worry about any more.
I'd also suggest actually copying on-the-air (W1AW or similar) so you get used to it, and especially try
to listen into real CQ nets. When I started hearing actual prosigns in use, etc, it messed me up
because I was so used to copying plain english texts.