The first issue is the cost of training. The company's practice is unreasonable. Now there are clear regulations on "employee on-the-job training". Basically, training that does not go abroad will not bear liquidated damages.

The second question, as long as you sign the contract, you should be paid. It is illegal not to pay.

The third question, if you write a manuscript, it is generally that the company reserves the right of distribution or even copyright, depending on how you write it in the contract.