All of those are terrible ideas. Let's see:
Backlinks for replies
Superfluous, messy
Stickies
See above
Mobile theme/s
No way, mobile users need not to post
better admin panel
Unnecessary, admins should stay out most of the time
youtube embeds
Worst idea possible
spoiler tags
Meh
ban list for mods / ban message screen if you are banned
Privacy violation. No need to maintain lists of any sort, banning on textboards should be very rare
There is no better text board than the Elitist Superstructure Of DQN - it is the elitest.
>>7
That's exactly what the other guy's saying he doesn't want, and I agree. Surprise boxes is irritating.
I mean, fuck it. If I wanted to be on some fancy board running livechan or vichan+pimp_my_ride, uploading 30MB .mkv files multiple times in each post and getting real-time reply indicators, I'd be there. But I'm not.
It sounds like you're writing your own board software. If that's the case, you should put what you want into it. If people like the result, they'll stay. You're not going to get high quality feedback going up to a bunch of people who are fine with what they're currently using and saying "HEY WHAT IF I MADE SOMETHING COMPLETELY DIFFERENT".