Andy, it sounds as if you are doing pretty well just a week after catheter removal.
One of the things we have learned here on the forum is that everyone is different, but for me the sphincter weakness following surgery is most obvious from activities which raise the pressure in the abdomen. Gardening is one, and surprisingly DIY activities like decorating where you use your "core muscles" to maintain position.
But walking can also be a problem, I think there is a temporary raise in pressure with every step. To be honest it is fine near the beginning of the day, but gets worse later on when the muscles get tired. It has got somewhat worse since salvage RT but manageable; last autumn I and my wife walked the Tour du Mont Blanc (early starts!) without problems.
With your progress this early, I would hope that in six months or so most activities are leak-free.