I'm not opposed to primary elections and caucuses, but I have a few misgivings.

Why do Iowa and New Hampshire effectively get to decide which candidates will most likely be nominated? Winning those two states gives a candidate a lot of momentum.  I think you ought to let most, if not all of the country have more of a say in that.  Of course that makes things more expensive, but the candidates seem to have no problems doing that.  If you really wanted to have one or two states at a time, they could consider drawing them at random, rather than having the same two states each time. 

Iowa caucuses on Jan. 3?   The election is in November.  There really is no reason why the election season should start so early.   All that does is give months and months on end for nominees to trash the other with tours, speeches and attack ads.  The election starts absurdly early- they could easily start the actual voting process in the summer.

Restricting the primaries to party members may make the candidates effectively chosen by the most fervent supporters, who are often not centrists.  Presidents have to be the executive for everyone- they should not be pandering to partisan extremists.  Perhaps letting everyone vote in all primaries, as they do in Wisconsin?  Then again if you did that, you might not want all of the primaries/caucuses at once (just to guard against one night of madness).

The media's focus on the presidency really makes everything else something of an afterthought.  I know that's the nature of the US system and nothing would likely change that, but honestly- how many Americans don't know the name of their congressman?