Let's see a further analisys of content of a decoded profile file.
As I said, first two and last two bytes contain no usefull infos. It's important to know just that, for a specific user Id, in original (un-decoded) .profile file, B0 Xor B1 (where B# is Byte at offset #) is costant, and the same for B0 Xor B14348 Xor B14349.
B3 - B1113 : In my experience, there are only zeros.
B1114 - B2113 : At the beginning, there is a sequence of 4-bytes integer; before finishing tutorial they are only 3, then 54. First number seems to me an offset for a specific point in a sequence of bytes that follow, then we have only a "0" in first case or 51 integer numbers that are "stats" in second one (some exemples: at 1138, number of practice games played; at 1198, number of black cards played; at 1266, total damage; at 1294, creature spell casted; at 1298, non-creature spell casted; at 1302, mana generated). Following there is number "1136" that I think is lenght of a starting sequence. Here we have 32 bytes that are generated when profile was created and that seem related to Id number, but 4 bytes after 12 are likely date of creation.
After a "FF FF" there are 30 bytes that I ignore meaning of, and then a strange sequence that is "40 06 40 06 40 06 40 06" when you just created profile and then can change a bit mainly in first 1 or 2 bytes.
After other 7 bytes, there is a very important area: 149 bytes that contain number of unlocked card! Every byte has 4 bit for istances of one card and 4 for another. It's possible to unlock all the cards, even premium ones, changing these numbers, and there is no check about limit of 4 cards, but I think we can consider cheating to obtain more than expected 976 cards. Following 364 bytes are zeros, but I think they are for cards that will be added in future, cause if you increase them, you increase number of cards that game declares present in your card collection!
Finally, after a misterious byte (maybe related to an error in my decode procedure), we have a variable number of "FF" till offset 2114.
B2114 - B2141 : Strange area that seems inserted after encoding of surrounding bytes. It has 24 zeros and then "E8 03 00 00", as far as I know.
B2142 - B4355 : I don't know...

B4356 - B4677: Mainly settings. First 3 bytes have to be considered at single bit level. At offset 4372, we have 12 bytes related to volume settings. Byte at 4384 is for "Quick duel" setting and can be 0, 1 or 2. In this area we have some other informations, like name of most powered creature controlled.
B4678 - B12805: Decks saved! There is space for 32 decks: any "slot" used has first 30 bytes for name and other 224 bytes. Empty slot have "FF 00" as last bytes.
B12806 - B12813 : Two "00" bytes and then one for "persona" selected. One byte "FF", and two that I don't know before one byte for difficulty (0, 1, 2), and one for cards order (0, 1, 2).
B12814 - B14345 : Notifications. First byte is "00" and second is number of notifications. Then any notification is 6 bytes long and I suppose has two bytes that are which type of notification, one with 4 bits for month and 1 bit indicating if notification is "unread", then one byte for day, one for hour and one for minute.
At the end we have two "00" bytes and then last two I yet mentioned.
I hope you could understand what I try to explain even if I wrote it badly...
