Shield Bash - A very interesting way to start a battle, but worthless in the middle of a fight, which I think is good. Somewhat dangerous, but I think the Minor Stun is a fitting reward for taking the risk of half your shield's health and rushing into a group of enemies. However, I'm concerned that this will make weapons that can inflict Stun be seen as less valuable, now that every knight can cause Stun. (Then again, if Sprites will be able to cause status, then the same could be said to whatever weapons cause the respective status.)
Dodge (Dash) - Way too generous with the invulnerability. It lasts for the entire length of the dash animation - including the moment at the end where you recover from the dash, and are left immobile for a split second. This feels like a moment where you should be able to get hit - and thus get punished for a poor dash, which I feel would make sense - but that isn't the case, and you can shield immediately after the invulnerability ends so that there's very little risk. Otherwise, I feel the long, 8-second cooldown is appropriate for making the dash an emergency evasive tool, and I like the distance it travels - far away from any threat, but not so far as to feel ridiculous. I found it useful for quickly avoiding area-of-effect attacks, like Mecha Knights' spin attacks and Giant Lichens' thorn patches.
There's another issue I have with both the shield bash and dash - they are both completely effective while you're Stunned. I think that being able to circumvent Stun's movement speed limitations through dashing is a bit too handy. Otherwise, I think that these moves are a very good addition to the combat system of the game. The Bash can be used to instigate a fight, and the Dash can be used to evade - a nice pairing. They don't make things significantly easier, but they still add interesting options to fights and are useful for dealing with the most annoying enemy attacks in the game.
I'm eager to see a test server with the Coliseum enabled, so that I can see how these abilities come into play in Lockdown!