Thoughts which may or may not help:
You can use Game Modes to set what Character class the player uses. For example, you could have HUD_GameMode and NoHUD_GameMode, with the “Default Pawn Class” setting setup respectively with your Characters (HUD vs NoHUD). Then for a given Level, you can use the World Setting “GameMode Override” to choose between HUD_GameMode or NoHUD_GameMode, per level, as you described you wanted. So Level_1 could use HUD_GameMode, and Level_2 could use NoHUD_GameMode. Learn more here: https://docs.unrealengine.com/latest/INT/Gameplay/Framework/GameMode/
You also mention Player Start, which I believe is more about where the player spawns, not what they spawn as. If you are trying to make player spawn location something more involved than just the one Player Start location, I suggest using the Level Blueprints or even more advanced using the Game Mode blueprints to drive player spawning, probably using the Event Begin Play event to do something with their location.