I just recommended someone else to go to the Sachsenhausen district in Frankfurt where there are a lot of applewine pubs. Dauth-Schneider is one of them but there are many others. The Römer (Römerberg) is the rebuilt old town for the main part of Frankfurt but Sachsenhausen is across the River Main. There is also a street which the locals call Fressgasse ('eat street') which has a lot of restaurants and you might find something good down there. You can stay in Frankfurt itself rather than picking an airport hotel as the city is only 10 - 15 mins away from the airport by train. The district around the railway station used to be somewhere to be avoided but it has cleaned up a lot in recent years so don't feel like you can't stay nearby.

Lavandula

On your arrival day, do you want to stay in Frankfurt or do you think you have to stay in Frankfurt just because you land there?

Mainz is not a bad base - very close to the airport but on the railway line convenient for going north. And a nice city, nicer than Frankfurt. Good museums (Gutenberg, ancient shipbuilding), good churches (a 1000 year old cathedral and a church with windows by Chagall) and you can take a ride on the boats up the Rhine or cross over to Rüdesheim for wine tasting. If you have time a trip up the Rhine from there, or else your train to Düsseldorf will go up the western side of the river and you can see the towns along the Rhine. On your last night I probably wouldn't stay further away than Mainz or maybe Wiesbaden, which is across the Rhine and about the same distance from the airport (about 40 mins), and which is 19th-century pretty.

Lavandula