I am upgrading The Zap Calendar V3 Add Event, on this Joomla 2.5 site:
cbbikeclub.org/submit-an-event?view=addevent&viewid=1

to a new Joomla 3.4 site 3.4 Joomla site with Zap Calendar V4

My new uncustomized Add Event form has many more fields than this old Add Event form implementation.
1 - What is accounting for the difference? Do you have documentation on customizing this form and hiding unwanted fields?
2- The old site category Add Event select is populated only with the 3 desired categories, and the select is shown open. My new form show all categories. How do I get it to show only the categories I want people to add events to?
3- I am a moderately capable PHP coder, but if you think that I should be hiring a Zap Calendar developer to complete this upgrade, please recommend one, or do you offer this service?