There should be a place in the lobby where players can go and get there experience kits, like prison has with the furnaces.
I would support but the amount of time you spend in the lobby before games isn't really enough for higher rank players to use all of their xp, so for now I'm neutral
I see what you mean. Doesn't look too hard to implement in the next map; a little redstone, an iron door, and a 3x3x3 room would be all it takes.
Nice idea. However it can easily be manipulated. There are plugins to create a better environment for this suggestion. This idea can also be interpreted in different methods which would make it less...... abusable (new word of the day).
I think you should just instantly receive xp by doing /kit [rank]xp. So instead of getting bottles, the amount of xp you would get from them would automatically be received, a bit like voting.