Firstly, the Strata Manager (or somebody from their Office) would only come out to your building when repairs etc are being undertaken if the Agreement / Contract that your Owners Corporation (O/C) has with them requires that attendance, and YES, they’d most certainly charge you to do that at the agreed hourly rate.
But why would your O/C want them to do that, when most contractors should be quite capable of cleaning or doing whatever is required without the Strata Manager or anybody else looking over their shoulder?
A Strata Manager and a Caretaker have completely different roles, and it’s when they “oversee” each other that duplication of their activities invariably arises, and when an O/C’s costs consequently increase.
Secondly, if your O/C wants to terminate the Agreement / Contract that it has with its Strata Manager, then that needs to be in accordance with whatever is in that Agreement / Contract where a minimum of three (3) months written notice is usually required, and be decided by a majority vote of Owners at a General Meeting; the Executive Committee cannot make that decision.
With regard to a Strata Manager handing-over the O/C’s records to a replacement, that’s what the three (3) months notice is for, but more critically, the O/C needs to have a firm proposal (incl, costs) from the replacement Strata Manager so that Owners can vote to appoint them at the same General Meeting.
Finally, if your E/C is of the opinion that its current Strata Manager has behaved fraudulently, then you need to discuss that with whoever it is that administers their License, in NSW that’s the Department of Fair Trading, but as your O/C has a legally binding Agreement / Contract with that Strata Manager it CANNOT just decide not to pay for their Services; best to seek some legal advice on that contractual issue.