Having issues broadcasting BitcoinJS transaction.
The miner fee will, by default, equal the inputs - outputs of your transaction.
I notice some problems with your code. You do not specify a change address to send the left-over amount. If I have an unspent output of 100 BTC and I want to send 10 BTC to someone else, I should have 1 input (the unspent output from the previous transaction) and 2 outputs (the receiver address and the change address). The inputs and outputs will look like this:

Inputs


Unspent output of 100 BTC


Outputs


Receiver address with 10 BTC
Change address (your BTC address) with 89.999 BTC


The fee will be 0.001 BTC since (in)(100) - (out)(10 + 89.999) = 0.001.
Hope I was able to help.