I wouldn't do it. Kidd is worthless. He's not even owned in my league and my league is generally deeper than most. He already averages under ten points a game and under 5 assists in recent weeks and now he may lose his starting job. So you're basically getting Brook Lopez for Davis and Lin. Not worth it. Bad deal. Do not do it!
Depends on how deep you are at the G position and C position - Lopez isn't exactly one of the leagues best rebounding centers but he'll put up more points than Davis by quite a bit. I haven't done a comparison but i'd imagine that Lopez is just as solid in the shot blocking category. If you're guard heavy then it's a good deal. I wouldn't say Lin is a top 10 PG this year but Lopez is a top 5 C.