1. The TR is proven to be a reliable clutch, sure there is bad examples around but every product has bad examples.
2. 20:1 is actually more oil then 25:1 so there's more then enough oil in his mixture.....
3. Loose retaining clips can and do happen from the factory, would you expect him to tear down every motor and physically check each engine? And they don't come loose when giving a few gentle pulls either as for the loading it up with wet stuff without a plug in? Never heard such rubbish.
4. My engine has over 30 hours and you should see how clean my piston looks, fuel and oil choice make a massive difference to the amount of carbon build up you get on a piston.
Once again another post by you with nothing but rubbish, you really are coming a cross as a very inexperienced person when it comes to RC and 1/5th scales and I hope that someone as equally as inexperienced as you doesn't come on this forum, read the rubbish that comes from you and takes it as gospal.