I separate cardio and weight training days to prevent burnout/fatigue. I've done too much in the past and my workouts suffered. Weight training is more important to me than cardio.
Getting old sucks. I can feel my T levels dropping more and more every couple years. I'm going to delay starting TRT until it's absolutely necessary, maybe 10 years from now.
I think you have a good approach, and the weights we use are pretty similar. If you're pressing 100 lbs DBs and DLing 4 bills, I think you're smart to delay the TRT.
I've gotten to the point where I just can't lift weights for too long - for me I don't see much difference it going for more volume, and would rather run, sprint, push the sled. All subjective though - we do what works for us.