Your sentences all sound awkward to me.
This is how I would interpret them:
[color=blue]‘Australia will win all the matches and that too with huge margins.’
You seem to be saying that Australia will win something (else) with huge margins, and in addition, Australia will (also) win all the matches with huge margins.
[color=blue]‘You will get tea there only in the morning and that too if you are a writer.’
You will get tea only in the morning and, if you are a writer, you will also get something else. (Whatever the “something else” is was previously mentioned.)
[color=blue]‘The kid went to the camp and that too without asking his parents’
The kid did something else without asking his parents, and he also went to camp without asking his parents.
I assume that the following sentences are what you actually wanted to say (I tried to keep the changes minimal):
[i]
‘Australia will win all the matches – and with huge margins too.’
‘You will get tea there only in the morning, and only if you are a writer.’
‘The kid went to the camp – and that without even asking his parents.’ [/i]
Here are some examples of sentences using ‘and that too’ that I found on the BNC:
One race remained, and that too was on a new and unknown track: at Estoril in Portugal. (i.e. at least one other race had also been on a new and unknown track)
Part of the pension can be taken as a cash sum when you retire and that too is tax free. (i.e. something else is also tax free)
They are also now out of the US sphere of influence, and that too is irreversible. (i.e. something else is also irreversible)
Another door led into the cellar from outside in the yard, and that too was kept locked. (i.e. there was at least one other door which was also kept locked)
.