Ruby on Rails, using Devise Questions with MS SQL

1) Is it possible to use devise without the following fields? If so, what are the steps to remove them?

t.string   "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.integer  "sign_in_count",          default: 0,  null: false
t.datetime "current_sign_in_at"
t.datetime "last_sign_in_at"
t.string   "current_sign_in_ip"
t.string   "last_sign_in_ip"
t.datetime "created_at",                          null: false
t.datetime "updated_at",  

2) I am using devise with Microsoft SQL Server where the user is created for me in SQL Server. Is it possible to use devise to take a pre encrypted password? I'm kinda stuck on that.

Thanks. Any help is appreciated.