Answer to "Can I increase Surface PRO RAM"Since ReadyBoost caches your RAM to a NAND device, you're not going to need or want to use a USB drive. The storage on the Surface Pro is implemented with a 6Gb/s SSD already, meaning that if ReadyBoost is enabled, you can simply use the main storage device for caching. If you are having space issues on your storage device, I would recommend a 256GB SD card. You can move some of the data from your SSD drive to the SD card, and then use the SSD for faster caching with ReadyBoost.
Answer to "Can I increase Surface PRO RAM"SSD - yes, can replace it up to at least 256GB