A:AnswerYes they can but keep in mind the warranty only covers parts that originally came with the computer. The max for the GPU is a 4070Ti Super or AMD equivalent (in size). The CPU I can't say with 100% certainty since I don't know which exact motherboard comes in this model.
A:AnswerThe motherboard may vary as we use different components we have in stock at the moment. However, I can provide the chipset information: it's B760 D5.