Yes, I can. CPU supports up to 32GB - and, since Sandy Bridge, the memory is connected directly to CPU.
The hard drive is using a proprietary connector.
That means, every time you buy a hard drive, you will need to buy "special edition for Mac" hard drive, which could be 1.5x times more expensive than usual hard drive with the same specs.
The Crucial website disagrees with you - states 16Gb RAM is the maximum. Could you post some evidence that someone has actually put 32Gb in a Macbook Pro and it is recognised, addressable and working? I'm genuinely curious to know if this works.
And regarding the proprietary connector - this isn't really a surprise. These are Apple machines after all.