This is the boat I'm in. Fortunately I signed up through 3Speak and they've delegated some HP to me. Someone also gifted me 0.001 Hive that I've now powered up... Not sure how I got it.
But their delegated HP expires 15 days after signing up. Busy until the end of the day tomorrow but then I have a few blog posts I'd like to submit before the HP expires.
I'd like to invite some more friends and encourage on boarding but the big obstacle is exactly what you outline. If you sign up for free(and have to wait a few days), you have very very limited actions you can take.
RE: Open Standard for a HIVE Account Referral System