AusBonsai

As a novice, I need advice.... again.....

I have this tall variegated pittosporum along our back fence that is struggling for sunlight due to the Crabapple on one side and a large Photina on the other (north side). Our plan is to cut back the Photina's at some point, but in the interim, I was going to air layer the Pittosporum because I love the leaves on this tree,I find myself looking at everything with bonsai eyes.

I've been circling this tree for weeks now and I thought the whole tree itself would be a great Bonsai prospect as the base is large, but not too big. So I've added a few photos from today and my questions are:

1. Is it too late in the season to attempt air layering, there are lot of branches that could be candidates?
2. How many air layers at one time is too many, I was thinking maybe four?
3. Should I feed the tree during the air layer period? This tree has just been left to its own devices for 16 yrs.
3. Based on the following photos, would this tree be worth digging up and potted for bonsai (post air layers)?

Thanks in advance

It is never too late to layer. Layers strike quickest in the growing season which is now. Layering in autumn and winter will still produce results, just takes longer.

You can put on as many layers as you like provided that each layer has its own leaves to help make food for new roots.
Feeding a tree will help it grow and be healthy. Healthy plants layer better.

Some people like big thick bonsai. I think that most trees have potential to be bonsai but only a few have potential to be great bonsai.
You could dig it provided -
1. you have a large pot to put it into initially and can afford a large bonsai pot ultimately. They all seem to expand quite considerably when they come out of the ground.
2.you have the stamina and persistence to get it out of the ground. This will not be easy
3. You are young and strong to be able to manage repotting, turning the pot as it grows, carrying it to shows, meetings, etc.

Thank you Shibui.

You raised some good points regarding digging this up for a large bonsai.
I might just let it stay as a "donor" tree cause I have no doubt I'm going to kill a few of the layers from it.

Cheers