Unless it is falling apart from rot or some such, no reason to trash it.
As I suggested before, I would advise an architect or structural engineer look at it for you - about $200-350 probably.
For the fix, you want a carpenter experienced in house construction - a rough carpenter, not a finish carpenter. He can probably aqlso help with the garage doors - unless they are crushed, he can probably fix them up so they work again right.