These are all good questions to ask. Given your previous experience, you will be sure not to be fobbed off. Your medical team will doubtless give you what they think is the best option for your survival. They are less concerned about your quality of life, which is fair enough for them but matters to you!
While chemo is still daunting, it is managed better than it was 40 years ago. I worked through chemo, because I easily could. Unfortunately there does not seem to be any reliable way of assessing how you will go until you start. Practical thoughts are whether you have any pre-existing conditions that chemo might particularly aggravate? You also need to consider that if your reactions are intolerable, you can stop. I didn't have radiotherapy, so can't speak from any experience but many people find that and work sort of manageable. Best wishes.