By lowering the fed funds rate, banks have incentive to borrow money from other banks in order to meet reserve requirements. The indirect effect is to free up cash. More cash drives down the price of borrowing. Lowered cost of borrowing opens the door to refinancing and makes home buying more attractive. It's quite simple, really. As for your other question, I'm a poor college student. I don't have cable.
unfortunately it is not as simple as in a textbook. fed funds is relatively unimportant rate when it comes to economic impact. when you go to get a mortgage you do not ask what is an overnight rate but rather what is some longer term rate (most of mortgages in US are fixed rate and longer than 10y - usually 30y, i.e. not ARMs). well let's refresh our memory and remember what happened to long end of the curve during previous 3 years when 17 hikes occurred - basically nothing! Therefore the house buyer was largely unaffected by a <i>gradual</i> tightening of money mkt conditions. Why now long rates should go down if fed cuts? There is really no reason. In fact as we saw 2 weeks ago long rates would likely go up on expected depreciation of USD and higher inflation expectations. Fed sees that (or at least saw it 1 day after the last meeting) and will not cut anytime soon unless there is some kind of total financial meltdown which, as an insider, I see as extremely unlikely.
None of these companies will be going away any time soon in a few years they will all recover to various extents.