The linear design is a function of the software. That cant be changed unless someone wants to spend approx $30k for custom software to be written.
I dont own the software, it is licensed. No other known bb software can cope with the 1 million plus posts that are on this forum from day one.
There isnt really any spare space for the other things you suggest. The sponsors ads contribute about 50% of the costs of running the bb, which amounts to about $2,500 a year.