Does all kung fu come from Shaolin? No.
Do all martial arts come from Shaolin? No. But Shaolin did influence almost every style of unarmed combat in Asia at some point.
Is modern Shaolin authentic? Authentic Shaolin, is authentic. It's rare, but it still remains. Also, many styles can legitimately claim a lineage from Shaolin anyway.
What is the difference between Northern/Southern styles? Not as much as people think. Ask /u/teacupcoffeecup for a good run down, he does a better stop than I would.
What is the difference between hard/soft styles? An emphasis on one or the other generally speaking.
What is the difference between internal/external styles? Eh.
Is Qi real? Yes.
Is Qi Gong/Chi Kung kung fu? Only in the literal sense that it's acquired through hard work.
Can I use qigong to fight? Yes.
Do I have to fight? No. You can always just stand there and let people beat you up, or you can run away.
Do Dim Mak/No-Touch Knockouts Exit? Eh.
Where do I find a teacher? Easily. Finding a good one, is much harder.
How do I know if a teacher is good? (Should include forms awards not being the same as martial qualification, and lineage not being end all!) Experience.
What is the difference between Sifu/Shifu? Cantonese versus Mandarin pronunciation.
What is the difference between forms, taolu and kata? Forms tend to refer to Chinese martial art practice, Taolu to performance, and Kata to the Japanese version of the first one.
Why do you practice forms? None of your business.
How do weapons help you with empty handed fighting? Try it out and see.
Is chisao/tuishou etc the same as sparring? No.
Why do many schools not spar/compete? (Please let's make sure we explain this!) Because you can't pretend to break someone's arm.
Can you spar with weapons? (We should mention HEMA and Dog Brothers) Real weapons, no. Practice versions, yes.
Can I do weights when training Kung Fu? Yes.
Will gaining muscle make my Kung Fu worse? No. Becoming stiff and cumbersome will though.
Can I cross train more than one Kung Fu style? Do whatever you like.
Can I cross train with other non-Kung Fu styles? Do whatever you like.