I'm honestly shocked by how uninformed this thread seems. We've discussed (in other threads) several of these issues with members of the staff, and quite recently.
The melee-bot problem was going to be solved but the A.I. was the problem, not what attacks they give the bots. The melee problem works like this: The game has to have a single A.I. for all of the Mastermind pets. Some of the Powersets for Masterminds use melee pets instead of ranged pets. If you take away the pet's [Brawl] they still walk up to melee range and attack stuff... they just shoot instead of using [Brawl]. Since the pets themselves don't think like a human when they decide what attack to use, the A.I. can't be easily re-written in a way that cares about what kind of attacks the pets can perform. They have to be moved into a position then choose their attacks semi-randomly. Fixing this would mean an overhaul of how all mobs, good and bad, made their decisions.
As for your other suggestions, I respectfully disagree.
[Photon Grenade] doesn't just have a chance to Disorient, there's another statistic called Magnitude that is also important. Overall, the entire thing needs to be looked at.
Everyone wants every Knockback effect changed to Knockdown. I'm of the opinion that all of them should be changed unless there's a good reason not to.
See the A.I. issues, above.
[Repair] is actually a unique sort of effect. Note that there are other ways to heal them, such as Secondary Powersets, Pool Powers, and dragging a Respite Inspiration onto their life bar. The effect of [Repair] is already strongly recommended by most of the guides to the Robotics Powerset that you can find online, and has strong flavor as well. Your personal preference that the mechanics look more like other healing effects isn't automatically the best design choice. Sometimes flavor matters, and sometimes others like the way something is.