Just so, are all camera tripod mounts the same?
Not the tripod itself is relevant for your question but the camera mount on the tripod is. However, camera mounts are standardized and you usually can use any tripod with any camera brand. You can even buy a tripod and a tripod head separately.
Additionally, are all tripod quick release plates the same? Quick release plate typesNot all quick release plates are the same, unfortunately. At one time, practically every tripod maker used a different system, but there has been a degree of standardisation since then, thankfully. Makers of cheaper tripods often use their own quick release plate designs.
Keeping this in view, are tripod mounts Universal?
I think it's safe to say that for consumer and mass-market professional cameras, 1/4-20 is universal. The 3/8-16 standard is in wide use today in photography, though — just not for camera mounts. It's common for lighting gear, including lighting stands and mounts.
Are quick release plates Universal?
Quick release plates are also known as QR plates, or simply tripod plates. They're small plates, usually made from metal, that are attached to the base of a camera using the tripod screw mount. However, the ARCA-Swiss type of quick release plate is a universal plate that will fit many tripods by a lot of manufacturers.