Howdy! The baulky motor problem sounds like an issue of timing. The ESC should have been default to an auto timing but I have run across a couple that weren't. If run that way once the motor overheats the enamel coating on the wires will degrade and short causing nearly the same condition.
Sounds like quite a bit of weight to the nose. If you get around to it, you may want to move the servos to the forward hole, getting the weight down will certainly help with getting it to float.
![Smile :-)](./images/smilies/icon_e_smile.gif)
Plane looks good though, great job! Glad you like it overall.
BTW, the 6500 Kv motor works much better than the 4000 Kv on these little planes. I have both and and have run quite a few test comparisons.
![Smile :-)](./images/smilies/icon_e_smile.gif)