Apologies for the basic Q's.. but... 1. is the processor user upgradeable? 2. is the RAM user upgradeable? looks it, but you waste the 4x 4GB. what do you do with them, sell them? as there are only 4 slots. Is it better to buy the 32GB option instead of buying the 16GB and replacing with third party 32GB RAM? 3. is the PCIe flash storage user upgradeable? ie buy base 256GB, then replace with 512GB or 1TB third party. Can you re-use the 256GB somewhere else via an adapter/sled into an external TB enclosure?