depends on how much damage it took
It is common for a newly planted lemon tree to drop its fruit; it will take a few years for its root-system to be developed.
Should a newly planted tree have the lower branches cut to encourage faster growth?
Yes .
Move it.
Yes they will eat the lower new leaves and ones higher up too if they can get at them. They will also have a chew at the bark and if left to their own devices will ruin a newly planted hedge. Hares will decimate a newly planted hedge. They chop off the stems and strip the bark. If either beasts are attracted to a newly planted hedge fence it with chicken wire--both sides.
4th
it's because you are watering it to much
You have to water the garden, so that the seeds can have enough nutrients to start off.
No. Dragonflies are purely carnivorous, they eat smaller insects.
every 3 days for the first month
For the first year make sure they have sufficient water and the plants cannot rock in the wind.
It doesn't matter where you are or how much rain you get you must water a newly planted tree regularly until it is established, this can take a year.