Without knowing your hiking ability and fitness level, it is impossible to say. I could easily do it. My parents could only handle Bell without the climb and definitely couldn't add on two additional hikes. I would choose a different hike than Bell. You can see it from the road and the path from the lower lot parallels the road. I usually recommend hikes that take you some place or get you to views that you can't see from your car.
We are both fit but not athletes ... I was thinking more time wise.... Fay morning , boynton afternoon and bell sunset...
Good to know about bell that was the one I was thinking of skipping
If not summer, yes. In summer you would need to do 2 of the hikes ASAP in the morning due to the heat. And by ASAP I mean at daybreak -5am. Parking will be a big challenge for the second and third hikes.
Check out my detailed trip report. Depending on where you go in Boynton to the Subway, to the Vista vortex and Fay canyon, the arch and beyond the end if the trail. We did multiple hikes per day. Parking is at a premium so plan accordingly