Yes. There is a myth that absentee ballots only get counted if the election is close, however, this is not true. Under Iowa law, every ballot must be counted.

Yes and No. In Iowa, you must be a member of a political party (currently: Republican, Democratic, and Libertarian) to vote in a primary election. However, anyone* can change parties on Election Day and vote. For independents to vote they must declare a political party.

*Precinct election officials may not change political parties within 30 days of an election.