I've been playing shooters on it for 3 years now. I spilled beer on one - I washed it - it didn’t dry at all, the contacts were lost :( I took it apart for spare parts for the second one. Nothing wears out, I play 3 hours a day. On the 0 button: well, no and no, I don’t need a calculator. By the location of CTRL ALT SHIFT - reassigned, it seems nothing is glitching with the system keys. I write configs with buttons for games on a flash drive. Using F buttons - I bought aluminum tape, pasted on some - they shine and it became visible. I heard there is phosphor ink, I think to try it.