@cheb First, please take a deep breath! There is a way to peacefully coexist in the world when we have bronchiectasis. You say "... I read I should be wearing a mask while doing simple things like filling the sink with hot water to hand wash dishes, or while cooking because of the steam. So, so , so, so many other things..."
Stop believing you must do everything you read, there are risks, but we also need to live our lives. Dr Jennifer Honda has great advice in this video:
https://www.youtube.com/watch
I have been living with bronchiectasis, asthma, and formerly pseudomonas & MAC/NTM for over 8 years (probably much longer) and at first it was overwhelming. Then my PCP and ID doc both said to me "Bronchiectasis is a disease you will live with, not die from. Take reasonable precautions and go out and live your life." That has become my mantra,

Kitchen steam? Keep your face out of it and run an exhaust fan. Let the dishes soak until the water cools, or assign the task to someone else. Turn the water heater above 130F to kill NTM in the hot water (there is much less in cold water.)
Gardening? Wet it down before you work. Only when dumping/disturbing mulch or dumping dirt do I mask.
Deep cleaning? I'm not aware of any risk there, unless you are raising a lot of dust, in which case a mask would be prudent for anyone with lung issues.

Now to your question about pottery - Yes, you can safely work with clay while wearing a mask - as often as you like. Our local studio has many older members with lung issues, from asthma to cancer, who do it. To increase safety, they also require all sanding to be done outdoors to limit dust in the air. Once fired, clay is completely safe, so applying glazes or painting carries minimal risk.

As for being treated, "beating" MAC, and stating healthy, it has been nearly 7 years since I quit antibiotics. With airway clearance and asthma management, using 0.2 micron filtered water, avoiding sick people, keeping my water heater at 130F+, and reasonable masking precautions, I have remained infection free. I care for my home, garden & small camper, volunteer, travel, paint, do fiber arts (many involving water) and hang out with friends, family & especially my grandkids.
Do not despair - we have all been where your are. Just "take reasonable precautions and go live your life"!