These are exactly issues I have with the current solutions out there, and it's something I've been thinking about solutions for, so I'm really interested in seeing what you come up with.
On the point about automatic bookmarking, I would almost like everything I view to be bookmarked, and then some cleverness to work out what I actually will come back to.
I also third the requests for cross-device sync. (I'm sure you already know this will be needed at some point, and appreciate it's outside the scope of an initial version.)