Hi, and welcome to the forum!
Majicontrast red is an orange based true red, the magenta red is more of a pink based red. It is essentially a bleach and colour in one step, but it is designed for virgin hair, so it doesn't take very well on already processed hair, which could be why you were told it's not recommended for a full head application, if your lengths are already processed. I had good success using majicontrast red instead of bleach and then using a semi-permanent red over the top.
However, be aware that as majicontrast uses a peroxide developer, it is just as damaging to your hair as bleach, and will still need a semi dye over the top to keep the colour vibrant. Permanent reds actually last for less time that semi reds, as the dye molecules in the permanent reds are larger than the molecules in the semi reds, so they slip out from under the cuticle easier. This is why permanent red dyes are notorious for fading.
I'd suggest using colour B4 to remove as much of the permanent dye build up as possible, then waiting a week and bleach bathing your hair until you get a suitable base colour (bright reds will take really well over a ginger base, so it shouldn't take too much bleach bathing), and then just skipping the permanent dye step and putting a semi red straight over the top. I've never used Crazy colour myself, but others have said it washes out really quickly, which could be why it had a lot of rub off for you. I've always found that Special Effects have the best staying power and least rub off, especially if you use a vinegar rinse as well, so maybe try one of those? They do some good pink based and orange based reds, and you can mix them together if you want a true red.
However, if you're determined to use majicontrast, I'd recommend only using a 20 vol developer, and definitely no higher than 30vol! 40 vol should never be used on a scalp application, as it's far too strong a chemical and could give you nasty burns!