Yes, you can delete your characters before the tavern opens

Using the Multiplayer Keep, it's possible to delete your characters before finishing the tutorial and being able to recruit characters normally. Then you'll be unable to finish the tutorial.
I just tried this out on the test server (account name = Dwedit). Care to reset my test account and give me 5000 pizza?

 

Heh, I was going to test this myself today. I'd suggest locking the MP Keep until the Keep on the Hinterlands unlocks. (You can still set your MP party by buying a starter deck.)

Also, players should be given the free Adventurer deck the first time they visit the Starter Shop, even if they haven't reached the point where Gary sends them into MP. At the very least, put in something to prevent players from buying that deck early (I've seen a couple threads of people asking for a refund).

 

Now I can also see that indeed, you can add starter characters to the party early on as well. That probably didn't get any testing during beta because you had to spend pizza to do this.
Maybe just lock out multiplayer entirely until you've unlocked the full tavern.

 

Sorry, I don't concur with locking out MP.

Reason being that if a customer wants to deviate from the tutorial and spend pizza buying starter packs, jumping straight into pvp, he should be allowed to. The bugs related to triggers can be reworked, the issue of not getting the free adventurer pack is fixable. The only annoying thing right now is the pizza refund for those who did not get the free pack.

 

Why not just have Gary give you free pizza for a starter pack instead of getting the starter for free via the event? I realize this might mean people choose one of the other MP packs first(ex smash bros) but is that really an issue? Just means if people buy a starter pack early they will.get their pizza back by following the SP tutorial.