I highly recommend BackBlaze for cloud storage backup. Your requirements are pretty difficult to hit with one piece of software - especially #2 and #4. I'm not sure you can find one solution that will totally meet your needs. You might want to try using something like dropbox with a service like backblaze. Use backblaze for backing up to the cloud and use dropbox for revision history + keeping files in sync across 5 computers.
Felt it here in Pittsburgh, PA - office building where I work shook a little bit (we're on the top floor) - it's a 7-story building with 4 of stories underground.
Also heard from my brother in Columbia, SC they felt it as well.
Finally added one of the more common requests I get - a dark theme - hit the "change theme" link at the bottom of the page and choose the "Infinite Dark" option. After changing the theme if you look at the little button next to the "gallery" button at the top you can change the color to your liking.
Use the advanced search for that (to get to advanced search click on the little gear looking icon right next to the search box) - then in that window scroll down to the "Display Results" line and change this to "As Posts".
For those not aware AMC gave Frank Darabont the boot from The Walking Dead - this tweet pretty much puts the blame on AMC looking to cut costs after paying more than they really could afford for Mad Men. That's quite sad if it's true.
Tapatalk should be working now - though I know I'm not having any luck w/ unread posts part working it just shows 0 unread which isn't correct.
Also I made some behind the scenes changes to a few things - if you notice anything odd w/ attachments/avatars/uploads please let me know.