The max items is a planned future addition. I'd originally planned on having it in the first version, but decided to keep things as simple as possible for the first go around. Max items will make an appearance in the next version.
When you leave out a label for a field, it's going to show the name that it's using internally. The same goes for repeaters. But because repeaters need to have the same field repeated over multiple times, they get the ID appended to the field name. That's necessary because an HTML form is all operating in the same namespace, so we can't just refer to "this_field" as "this_field". Instead we have to refer to it as "this_field for repeater item ID 1234", i.e. "this_field_repeater1234". That's what you are seeing in the screenshot.