Have you checked out https://github.com/potenza/bootstrap_form? We just added support for Bootstrap 3 and it's very lightweight.
We support almost all of your requirements, but we're still working on a good solution for date and time selects as they are currently stacked by default.
Here's an example form in erb:
<%= bootstrap_form_for(@user) do |f| %>
<%= f.email_field :email %>
<%= f.password_field :password %>
<%= f.check_box :remember_me %>
<%= f.submit "Log In" %>
<% end %>
And the output:
