I have added an extra mango in the pudding for more fruit element, over and above the canned fruit. I would have loved to add an apple but ran out of it.
For the cake base, you can definitely use store bought cake to save time.
Instead of using fruit pieces in a can, you can use fresh fruits and make the sugar syrup to soak the cake, but heating a cup of water with a cup of sugar till well dissolved.
You can avoid the nuts if it is not to your taste, or even use praline or crushed peanut candy - I am sure it would give yet another taste to the whole pudding.
Adjust sweetness as per preference.