It is a waste of money to make seat reservations in the US at $11 each for travel in Germany. Rather, if seat reservations are desired, they can be made in Germany when you arrive. (It now also appears possible to make seat reservations on the DB website at E 3, each without also purchasing a ticket, but I haven't tried this yet). That would be helpful to people with a rail pass.

And ICE definitely means Inter-city express.

My experience is that single travelers in 1st almost never need reservations in Germany, except maybe on key holiday weekends (probably fewer business travelers in 1st on a Sunday than on a Friday, though).

Now, I'm wondering whether I should get a seat reservation on a midday IC train in 1st from Frankfurt to Cologne via Rhine Valley on the Friday of the Pfingsten holiday (5/13). Anybody have any thoughts?