There is a good sum up of various sources on Napoleon's childhood in "Gloire et Empire" magazine, #80.

According to young Bonaparte's writings, his dream of greatness was about delivering Corsica from french yoke - something he probably did not explain fully to french officers, and not exactly dreams of world conquest. So much for your warmonger profile.
Only after revolution and the quarel between Bonaparte clan and Paolist did he fully adhere to jacobinism and french career.

Loneliness is also often explained by his origin : native corsican speaker, with less ancient and prestigious nobility than his french consorts (*), he found more satisfaction in books than friendship.

(*)Like in Spain, nobility in Corsica had no precise rule and was largely shared amongst the population. Official recognition of nobility by the French kingdom, thus education of the children in French military school, was part of the deal proposed to some happy few to rally pro-indepence Corsicans.