Luca,
From your posts, is appears you have chosen the CBA over PA. Being as you also had concerns about improvisation, I thought I'd add some of my experience on this subject. Others may disagree, but my approach has yielded results for me.
My major objective in my music path is to be able to improv at will, and sound good doing it. When I started CBA-C, I started with scales [chromatic 1st.] while perusing the i-net for direction. Most advice was to learn to play on the outer 3 rows first, then move onto the remaining 2 rows. I followed that advice for my first 10 months, while learning songs I knew from my past [not condusive to improv].
I then made a radical change. Having observed many players [and good one's, too] only using the 3 outer rows when playing, I thought it a waste of two perfectly good rows. One of the greatest advantages to the CBA is the versatility/options for fingering. The piano has one way to play two successive notes. The CBA has four ways to make the same passage if you use all five rows.
I stopped playing/learning songs, and instead went back to basics. I focused on two things: mastering the scales [still working on this one] and "centering" my playing on the middle 3 rows. While I learned the 3 scale patterns necessary to play all 12 scales on the outer 3 rows [recommended], "centering" on the middle 3 rows only requires one pattern. This approach also positions notes that fall out of the "center" pattern to be easily accessed on rows 1 and 5. When a big step is required to stay "centered", often the note is right at hand on 1 or 5. The fingering is also usually easier when "centered". I find I use 2-3-4 the most, with row 1 a close second. I use row 5 occasionally compared to the others. I also found I had a hard time converting/moving my already learned songs over to the "center". That muscle memory has a very strong influence. A good reason to get it right the first time.
When doing repetative scale practice, I now start with straight scales, running the full length of the keyboard, not just one octive. Moving between octives can be a challange at first. Then, after 15-30 mins of straight scales [chromatic, all 12 keys, various pentatonic, blues], I start to mix up the scale order, looking for interesting, good sounding combinations of notes. When I discover some combination I like, I then repeate them over and over in the hopes I'll remember them next time I play. I have been doing this for the last 3-4 months and I am more than satisfied with the results. I can't play any more songs than I did 6 months ago [although I play them much better], but, I can sit down and just "play" the thing. And it sounds pretty good, too. This is improv. It's a very satisfing feeling to play what's in your head, however simple.
It is crucial to know where the proper "sound" is located on your keyboard. Not necessarily the name of the note, but the sound [tone]. If you read music, DON'T!!! Improvisation will only come thru instinctively knowing where to go. I have read many posts by people who have played an instrument for many years, but lament they are lost without "the dots" to guide them. Their only shortcoming is they never learned where the proper "sound" is found to fill their imagination. That comes from messin' about as described above.
While I believe a skilled dot reader can learn to improvise, I also believe it is much better to learn to improvise before learning to read music. Improvisation requires freedom, the opposite of the regimentation of "the dots".
One last bit of "advice". I wish I had learned the bass side before learning the right hand. It's not all that difficult, despite the number of buttons. I now believe it would have been easier to get the "rhythm" side down first, then add the "lead". Your piano experience should be of benefit here as you have experience with the two hands doing different things at the same time.
You will not likely find a mainstream teacher who will agree with my approach. I don't have a teacher, so I am unencumbered by tradition. The biggest difference would be "centering", instead of learning the outer 3 rows first. [BTW: The outer 3 row approach prepares the player to adapt between 3-4 & 5 row boxes. Not an issue for me as I will only be playing 5 row].
Good luck on your decision to go squeezy. The CBA is a fantastic instrument with it's design centered around playability. You will discover many nuances associated with the CBA not found in any other instrument. I love it and haven't looked back.
Press on...
Waldo