Yes, the engine is OK. Re changes, I will definitely reinforce the landing gear block, from inside with carbon fiber. Also carbon fiber as much as I can see the firewall, that is a weak point of this plane, for engines my size. 40cc. Also make sure the stab is well glued, take off the monokote and make sure it is wood to wood, with 30 minute expoxcy. The wings are OK, will still go with only two servos, never had a problem, and I like the look of the strutte that runs both ailorons. Again, I will use this plane only for winter, so skis will be the way to go. It is a wonderul plane, and a great kit for the money. even at full price. Also will re glue or cover with fiberglass cloth the small wooden pieces that have the holes to put the bolt through to reach the blind nut in the cowling ringg. This is a very weak part of this plane. The wood is cheap and most probably will go to a better plywwod and a little thicker.
Wil coat these pieces with epoxy and very light fiberglass cloth.