Honestly, architecture doesn't matter all that much as long as you have your OS kernel and compiler(s) ported. MIPS, Alpha, ARM, and Power all run pretty much any open source software you could wish for, although I can't speak to UPU as I've never heard of it.
Not necessarily. There are many use cases where there is no disadvantage to a fast hashing algorithm. For example, secure hashes are commonly used to guarantee that data has not been modified. (I believe that PHP uses a hash for this purpose, as it is much faster than running rsa on the entire message.)
What this REALLY tells us is something that we have known for a long time: fast hash functions are suboptimal for password "storage"/verification. We need to use something slower for dealing with passwords, such as bcrypt, which can be made arbitrarily expensive.
Now if only TFA had actually said anything specific about the hardware... Here's hoping for Cortex-A9, perhaps OMAP4? ChromeOS isn't very interesting to me, but I would almost certainly buy one to use with a real distro.