But that's precisely my point. Pruned Ethereum nodes hold _all_ blocks and therefore are full nodes. In Ethereum, unlike pruning Bitcoin nodes, old blocks are not deleted.
Parity does not run on the EVM, it's a local node processing a local copy of the blockchain. You can create normal accounts which are just private/public keypairs you have full control of without anything "being in the cloud" or "distributed". What you are referring to might be the vulnerable multi-signature wallet itself, which - once deployed - runs on the EVM. And that only affects a fraction of Parity users.
Not at all. Solidity is just the most widely used language for the EVM. There are also Mutan (dead), Serpent (dying), LLL (recently revived), and Viper (being drafted).
The code was reviewed by two other developers and this is the standard procedure for any pull request touching any of our code-base. The mistake that happened here, that security-relevant changes were not highlighted accordingly and should have split out in a different pull request which requires more eyes (sample: https://github.com/paritytech/contracts/pull/48).