The bottom of the EVO bamboo is about 5mm. So the x-small would probably work, although it would be tight. Fwiw, you can do ISO cleaning of the bamboo with q-tips, unless you've somehow got crud inside the heat chamber (the middle section).
So you are
not combusting on max but wonder if maybe you should be? I wouldn't be concerned at all. I can probably force my EVO to combust on max with the right load for that and using a very strong pull. But otherwise, it probably won't. And my unit works perfectly; it certainly does not run cold.
Re the male power cord connector, as long as its barely moving and you aren't getting a short or power outage, I'd leave it be. It's been a long time since I've had a unit opened up, but IIRC that connector is inserted into the housing from the outside and held by a bezel and then behind the connector inside there are a couple wires which run to the circuit board (just behind the switch). Damn but I just can't remember what secures the connector, but it may only be the tension between the bezel (on the outside) and the connector body (on the inside). If so, then moving the power connector a lot could conceivably dislodge the wires, but very small movement should be OK. If I'm wrong (likely someone will correct me if I am) and the connector is directly attached to the circuit board, then you probably don't want it moving; in that case, I'd fire an email off to Support to get their opinion.