I like the GP5000 tire or even the 4000 if you find any. They should be cheaper since the 5000 replaced them.
For petals I like the fairly inexpensive Shimano PD-M520 but they are mtb pedals and require the 2 bolt cleat so you have to have a shoe that will take them.
I too only hear out of one ear. Its not really a big deal for me and even helps sometimes. When driving a convertible I can hear every word my wife says but I have to yell at her since she has noise in both ears. If she is driving I can't hear anything but wind.
I don't use a earbud on the trainer since its just the two of us at home and she hasn't complained yet. How about pedaling a little and getting everything set right then putting the earbud in? The derailleur should stay where you put it from ride to ride unless you are going back and forth from big to little ring.