I believe if you look at red rescue team it is the same.
You may recruit Groudon after the end credits of the game.
you cannot recruit Pokemon for completing missions in blue rescue but u can recruit via missions in time and dark
after you defeat groudon
You can get volcanic pit after recruiting Groudon.
you fight off groudon and kygore
You can't recruit any Pokemon at the Makukita Dojo.
You can recruit Registeel in Pokemon Mystery Dungeon Blue Rescue Team but his recruit rate is 0.01 percent. Registeel can be found at the Buried Relic and his friend area is the Ancient Ruins.
you are able to get groudon later in the game and the flying red and blue dragon, but you have to beat the game
no but you can, if you want to recruit it then i suggest you have something to make it easier to recruit Pokemon
i am not sure about if they are the leader but they can be a partner
There are hundreds of Pokemon that you can recruit in Pokemon rescue team. It would take hours to do everything. After you beat the game then you can recruit more Pokemon and buy more friend areas.
By beating rayquaza and having a friend bow, lvl 100 and max iq. Dont recruit anyone else. Save at midway so turn off if you dont recruit so you can try agian.