回複：回複：I am back.

I have spent last several months…meditating, and I found it (adding "is" or "was" here?) a very productive experience.

ð  Not necessary. “a very productive experience” is indirect object, as "annoying" in “I found her annoying.”

I walked aimlessly on the ("the" may not needed here?)  King street at Toronto downtown, 

ð  Can be dropped. Normally, articles shouldn’t be in front of the street names, unless you really want to emphasize a fact that it is something famous, one of a kind, like this “King Street” – Canada’s financial hub.

If I was (were?) to put on a stage

ð    " Be + infinitive" to express a planned event. “I” was actually doing something toward “my” goal, which was not an unattainable wish.

all I needed to do was not pass (to pass or passing?) out or not trip (to trip or triping?) myself.

ð  This is a fantastic suggestion. I would have used infinitive form if not for a fact that all the books I have read so far (about 5 novels) dropped “to” in this sentence pattern.  I don’t know why those authors wrote unanimously this way.  This is the only place in my story that I was simply copying a usage blindly. Needs more research on this one.

I felt so grateful to this kindness (adding "act" here?)

ð  I feel it clumsy to add "act" here and "kind act" sounds weird to me.