Concider the following scenario:
A 200 ton 'Mech walks/runs at 60km/h straight into a 20 story building.

Think they'll put some sort of red faction-esque building-smashing-system in there?

Maybe?
 
Hopfully, for the new game they release a demo.

I'll bet they give the buildings a certain amount of health so that you can blow them up with enough firepower, but they don't fall over as soon as you land on them, so you can walk on them. Unless they're tiny, in which case they explode.

I highly doubt any Mech over 100 tons due to limitations of the Myomer Fiber Bundles that are used as artificial muscles. This is highly outlined in the books, not saying that they could deviate, just pointing it out.

I would hope so. They stated the trailer they the release...hey right around the time this thread was made, was created using in-game assets. Of course you have to take that with a grain of salt, but here's hoping!