Thank you for your question.
Certainly, the election timing is important. The United States would be much better off if it had four-year terms for the House of Representatives rather than two-year terms. In fact, two-year terms are very exceptional. Almost all countries have four or five-year terms—although, of course, that may be cut short if the parliament is dissolved.
The weaknesses of the FPTP system in the United States have to do with the usual weakness, that it's not representative. In fact, in several of the last elections Democrats won a larger percentage of the vote than Republicans, but because of intentional gerrymandering and the way that populations are distributed, these Republican victories have occurred. Especially if a party actually wins the majority of the vote, it seems to me quite wrong that that party does not have a majority of the seats.
In the United States the further problem is with primary elections on the whole, which of course were meant to make the system more democratic. But these tend to give special strength to extremes in both parties—in the case of the Republicans, the so-called Tea Party especially.