Many Corona kits seem to have missing parts. If you are missing a part and you bought the kit directly from Lite Machines, call them and explain your situation. If you bought from a retailer and not Lite Machines, then talk to your retailer about the missing parts. You may want to finish most of the model before reporting missing parts so you don't need to call multiple times.
The general consensus on the Ezone regarding the Fusion-7 motor is it's not very good. People have reported the motor dying after as few as 5-10 flights. The Kyosho Atomic Force seems to be the best alternative brushed motor. It is available from Tower Hobbies.
Make sure there is enough room between the two cyclic servos for the servo arms to rotate freely without hitting the other servo. If the servo arm rubs against the other servo, your front/back cyclic control will be sluggish and hovering will be very difficult.
The manual recommends using one 4 dot blade grip and one 6 dot blade grip, but the heli is more stable and easier to hover if you use two 4 dot blade grips because the headspeed is higher. Later on if you want more lift you can switch one of the blade grips to a 6 dot blade grip.
If you are at a high elevation, you may not get enough lift using two 4 dot blade grips, however. In this case, you should use the manual-recommended grips.
The labels on the main rotor blades seem to be attached using the world's stickiest adhesive. The residue from the adhesive can be easily removed using WD-40 or Goo Gone.
DO NOT USE ACETONE. ACETONE WILL MAKE THE BLADES BRITTLE. THE BLADES MAY SHATTER WHEN THEY HIT AN OBJECT.
The Fusion 35 controller on the LMH Corona is a relabeled Castle Creations Pegasus 35.
The Fusion 35/Pegasus 35 seems to have trouble arming on many transmitters. If you turn on the transmitter, then turn on the Corona and do not hear two beeps, then you are having this problem. To fix this problem, you need to set a lower endpoint for the throttle channel on your transmitter. For a Futaba 9C, go to Menu->End Point->THR and set it to 125/125.
Many people make "tail boom protector" for the Corona to protect the tail boom from boom strikes. This is usually foam wrapped around the tail boom or a strip of 1/4 thick balsa or 3/8 dowel tie wrapped to the tail to prevent the rotor blades from denting/bending the tail boom. Other people use a "rotor deflector" which is a piece of wood or angle aluminum mounted on the tail to deflect the rotor blade.
The feathering plate should be parallel to the swashplate. If these are not parallel, then you may need to loosen the main shaft and slide the main shaft down a little bit until the two are properly parallel.