a. Cost will obviously be a factor in choosing where to hold your event and what services to provide, but so will attendance. You want to select a location that is centrally located and well known for organizing other successful events.
b. A hotel is certainly appealing, with enough meeting and personal rooms, and can help you plan a stress-free meeting/event. Especially, if you have international (keynote) speakers and/or participants it’s easy to have them all under one roof.
c. Your ideal keynote speaker may be Mark Zuckerberg, but realistically you probably need to go with a less-pricey option.
d. Consider polling participants from past events to understand what’s most important when attending such an event and make selections based on this feedback.