"This causes the EDB to block other EDBs"
All EDBs have this feature.

"slash through things at a reduced energy cost." Given your explanation, I propose we let you have this. Your EDB is highly efficient. However, due to the additional complexities, the EDB is slightly less powerful. Something like x.8 cutting strength, x2 efficiency sounds fine to me. It'll still block EDBs fine and cut through most Kensai Models, but it might have trouble penetrating through superheavy armor models like the Jaeger family in a single cut.

I'd say the overclock mode is fine, but with a different source (otherwise it would be a system that would really need to be refitted onto everything because it's that good or given an additional restriction). Arlanians are capable of using the King Hand system, and I notice this mech doesn't have that. Why not have Alain design a system that allows Arlanians to use a similar burst of energy to instead temporarily increase their speed and weapon power for a few seconds? This would explain why it's an Arlanian design without the King Hand, as you wouldn't want to overexert the pilot and burden the mech with two of these systems.

If you prefer to keep it mundane, my added restriction would be it is only usable for short bursts at a time due to overheating problems.

Balance aside, here's my gut feeling. The frame you've come up with.. Doesn't feel like what you've sold it as. The main mission behind your Kensai is that it should be modular, but there isn't anything in that design that seems to emphasize that. It has hands, a retractable EDB, a sniper rifle, and two inbuilt systems. There's nothing about this design that makes it what you set out to achieve. Gut feeling aside, I'm fine with the design. It works. I'm glad to have another design. But, I would suggest taking some time or some advice in order to make it more like your concept of a modular Kensai.

In Summary:
With a few tweaks, I'd accept it. However, I suggest(but it's ok if you decline to) you might want to put a little more work in, as it's acceptable, but I feel you missed your target.