The teambuilder has a hard time selecting Type: Null. Sometimes, when I try to either select it by either clicking on it fro the list or typing its name and pressing enter, the text in the box where you search for Pokemon just says "Type" and nothing happens. It seems like the only ways to do it are to edit the text file directly, or to select another Pokemon, begin a search for something that isn't a thing (for example, type "d", "sdyfgsxgf", or "Type: Null") then to click on another box (item, ability, or move) then click back to the search box. Doing so will not bring up the Pokemon list (another bug) and you can then type out either "type: null" or "type null" (caps don't matter) to finally put it on your team.
As for the other bug, if you leave an invalid Pokemon name in the search box, clicking on a text box for items/abilities/moves and and then going back to the search box won't update the selection list. Selecting something at this point will put the selection into the search bar. If you selected a move or ability, it will search for Pokemon with that move or ability, though you can not remove the search filter. Selecting an item will just put that item's name in the search box, and you'll have another invalid Pokemon name in the search box again.
Another bug I found while testing the previous one is that the full names of valid moves and abilities count as invalid Pokemon names, so if you type it out but don't click "filter" you'll activate the previous glitch.