They keyboard player from Bon Jovi & the Wild Ones, Mick Seeley, states that he wrote the keyboard riff in Runaway. On his facebook page it says:
"Remember the distinctive keyboard intro to Bonjovi's first hit "Runaway"? That was penned by NJ songwriter Mick Seeley. "
Just few weeks ago I got this book and interesting enough its got quote from George Karak (co-writer of Runaway) saying he had the whole song pretty much written but Bongiovi did make some modifications *on lyrics* and yet they split it 50%/50% because that was common those days.
And yes, bonjovi90 mentioned the Desmond CHild interview about Bad Medicine pre-chorus. That's from finnish TV show "Rockstop!" from 80s where they interview DC briefly.