Mr Happy: ".....so conclusion: B# exists but is commonly known as C!"

Pretty much so, however, some musicians may use the term B#, when counting off, to another musician, as designating a half step up. You might consider, using 1,2,3,4,5,6,7, and denoting the half steps going up or down, depending on the direction of the movement, in the progression. That way, the intervals are ALWAYS the same, and the only thing that changes, is where you start, as 1.

For instance, let's say, in the key of E, on your guitar, you may start counting from the fat E string, open. That would be '1'..and the scale starts counting up from there. Now, if you start from 'F'(one fret up) F becomes '1', and the scale counts up from there, using the same intervals. You might hear, or have heard, musicians say to each other, "Grab the '5', and take it to the '7'" That means NO MATTER WHAT KEY YOUR IN, but depending on the key, you know to grab the 5th of that key, and go to the 7th, (or 'sol', to 'ti'). Another example you might have heard, or even said, is, "OK, its a blues tune 1,4,5 in 'A'" I trust you are familiar with that. ..or in a lot of folk or country western, C,F,G.
It is a lot less confusing, and faster, for many players, especially in live jams, or practice sessions....THEN, if someone calls out," Go to the the 'flat 5'"..its a half step down..or if they say, "Go to the sharp '6'"..you know to raise the '6' a half step..which, for all you know, could be a 'B#', or 'C'....or anything, depending on what you call '1'(the key of the song).

Another very important handy hint, is to LEARN THE MAJOR SCALE IN ALL KEYS! You will quickly find, that the 'patterns' are all the same, just that you move '1'('Do') a half step up, when beginning your scale. There are FIVE predominant patterns of the major scale on the guitar. You can note the difference of the 'grand bar' shape, as opposed to the 'double bar' shape, or the 'open C' shape. They all have different major scale patterns. Being as those are the most common, it would do you wonders, to learn those shapes!!..and practice them, till you don't even need to think about them, AND play them 'legato'(very smoothly) from one note to the next, (whether they be on the same string or not), using a 'back and forth' picking technique.

I'm sure, somewhere on the 'net' you can find the patterns, and print them, to use for reference.

There's more, but if you get through this, which is a lot simpler that it may sound, let me know...

AND remember, "SPEED IS A BI-PRODUCT OF ACCURACY!!!"..go for accuracy!!!

Regards,

GfS