This would be an oligarchy. An oligarchy is where power is given to a group of people, be it nobility, wealthy people or people with family ties. Land, people and a form of sovereignity do however.
Answer:
The vassals had to serve lords because he promised to serve a lord in exchange for land. ... I think that the lords benefited more from feudalism because of the systems of promises that governed the realtionships between lords and the vassals
That is true and they also wanted help in making countries, to be like France and Great Britain, in their country. However, neither have happened quite yet.
Answer: WWI would still have occurred.
Explanation:
Even if Ferdinand were not executed, there were still tension and hatred towards Austria-Hungary, and Ferdinand and his wife. Other factors that also contributed towards the start of WWI were Militarism, Alliances, Imperialism, and Nationalism (M.A.I.N)
Just remember that Germany will be blamed for the war, mainly because of it's nationalism and it's desire to acquire more land and power.