What activities should I avoid to reduce bursa irritation most?

The kneeling data is the only real signal here, and it points at load, not at walking.

The question is which activities to avoid, and the retrieved records answer that for one activity only: kneeling. In a workforce survey, knee bursitis prevalence climbed with daily kneeling time, from about 0.1 in 100 with none to 3.6 in 100 above four hours a day [1]. Heavy perceived workload was also a listed risk factor [1]. Squatting was grouped with kneeling as a posture risk [1]. That is the whole of the direct activity evidence in front of me.

Everything else is inference. The records on anserine bursitis describe it as a common inner-knee pain often sitting alongside knee arthritis and diabetes, and they say the underlying risk factors are poorly understood [2]. A large cohort found these bursa swellings did not independently predict new knee pain or new arthritis [3]. So the bursa is more often a marker of load and joint trouble than a disease of its own. Cut the kneeling, the deep squatting, and the sustained crouch. Kneepads and a stool beat willpower.

The studies that would settle the rest, a trial of specific activities against rest, are not here. Nothing in these records tested stairs, cycling, running, or walking volume.

My call: avoid prolonged kneeling and deep squatting first, since that is the only activity with a dose-response in the data; treat the rest as untested. Confidence: low.