Could "fake" transactions be created to increase blockchain traffic such that the Bcash guys would love to do to bitcoin core Or attack bitcoin network as "Deny of Service" ??
If you mean fake transactions as indicated in the OP, to the best of my knowledge, it's not possible. There are a number of checks it must go through before the transaction is moved to another. This particular transaction is bound to fail such checks.
But if you mean fake transactions where smaller amounts with lower transaction fee are created to increase the blockchain traffic as a form of denial-of-service attack against bitcoin by the Bcash guys then its possible.