Thanks for your comments and suggestions! I especially appreciate the comments about muscle balance - that DOES make sense to me, but what FEELS comfortable to me now is riding in the most difficult gear all the time. And, I feel like I would be MORE comfortable with GREATER resistance to push against.
I would like to up my mileage from 30 or so at a time to maybe 50, but I don’t foresee having a need or a desire to ride a longer distance at one time and I am happy with a speed of ~15miles/hr.
I am still learning about the technical side of biking and it may take me a bit to process all of your information.l, but it is definitely helpful.
PS I am NOT an athlete by any stretch but have done step zumba with weights 2x weekly for many years, usually for a total step count of ~3 miles/hr, plus weight training, plus bike riding for about 6 years now😜