What information can an insurance company request of a someone who was in an accident?

In order to claim wage loss, you will have to provide documentation of the wage loss.  That is why the insurance company is asking for the pay stubs.  If your employer has some form that just says you lost X amount and your hourly rate is Y dollars per hour and you were absent from work on the following dates due to your injuries from the auto accident, that should be sufficient in itself to establish evidence of wage loss.

Since your accident was only two months ago, you don't want to provide wage loss or other information until you complete your medical treatment and are released by the doctor or are declared by the doctor to be permanent and stationary which means you have reached a point where no further improvement is anticipated.  The reason for waiting until you are through with medical treatment is so that you will know the total wage loss.  Your personal injury claim filed with the at-fault driver's insurance company  when you complete your medical treatment should include your medical bills, medical reports, and documentation of wage loss.  Compensation for the medical bills is straight reimbursement.  Compensation for wage loss is straight reimbursement.  The medical reports will document the nature and extent of your injury and will be used to determine compensation for pain and suffering.  Compensation for pain and suffering is an amount in addition to the medical bills.  If you are dissatisfied with settlement offers from the insurance company, reject the settlement offers and file your lawsuit for negligence against the at-fault driver and registered owner if the registered owner is someone other than the driver.  If the case is settled with the insurance company, NO lawsuit is filed.  If the case is NOT settled with the insurance company, you will need to file your lawsuit for negligence prior to the expiration of the applicable statute of limitations or you will lose your rights forever in the matter.