My resting HR goes as low as 44 sometimes. 46-48 is totally normal for a cyclist. I have a riding buddy who's much better conditioned and talented than am I whose resting HR is 40. He has a note to that effect on his RiderID, not a bad idea. I suppose I have "low blood pressure" for the American population of my age, usually 106/68, but that's actually what the medical community would like all of us to have.

Your TRIMP of 88/hour is quite normal, so my guess would be that your zones are somewhere in the ballpark. My Strava TRIMPs run between 75 and 110 per hour, depending on my level of conditioning. The better shape I'm in, the longer I can hold high HRs. On a killer 3 hour ride when I'm in good shape, my average HR will be as high as 92% of lactate threshold HR (LTHR). Your watts/kg is also normal for average riders of your age.

If it's OK with your cardiologist, you should push your effort and HR up into the panting zone on climbs of less than 10 minutes, so maybe ~142, maybe higher. That's how you get faster. That'll also bring up your Strava average watts/kg. But do ask that direct question of the doctor.

You should push your median cadence up. 85 would be a good target. A higher cadence will increase your HR slightly (no big deal) but will also increase your endurance (big deal.) Running a consistently higher cadence might temporarily drop your average watts a little, but that'll come back up as you adapt.