RE: DLE-111 first start... warranty used, but things are looking good.
Judging from your video considering that you bought the engine from us i would have to see clower pictures for inspection.
The engine was running fine as it should have but the four stroking and struggling to stay running could mean to rich of a mixture.
In regards to a bent crank shaft literally this would be a first for as long as we have sold DLE Engines for an engine to come straight out of the box with a bent crank un likely.
But from watching the video if the crank was bent it would shook terribly and even possibly caused your engine test stand to fall over from the vibrations if it wasnt secure.
Do me a favor and take throrough pictures for me and email me the pictures.
Also failure to tighten all the screws down correctly allowing the minimal amount of play or tolerance can cause a screw to sheer or bend then possibly loose the prop. Important to always tighten all screw down and use blue locktite to ensure the screws stay secure.
And i have had an DLE 111 lose its prop during flight and the engine died before so that can cause the engine to die.
So for to say the crank is bent and vibrating It does not seem to be the case. Again thorough pictures would help me to make a determination.