Linux thin clients

I have a lot of software-related questions in my head, maybe I can find answers to them with you.

• When there are many PCs in an organization, the question arises of how they are managed, fixing bugs in software, installing additional software, getting rid of viruses, etc. One solution to these problems may be the purchase of a server (s) and several terminals equal to the number of employees of the organization, plus some quantity for replacement in case of malfunctions or the arrival of new employees. In general, the number of terminals can be taken into account in the company's development strategy, as well as the percentage of equipment failure (world statistics?). The OS on these terminals is “loaded” through the network from the server (s), i.e. we come to the centralized management of all equipment in the organization. This solution also makes it possible to solve, to some extent, the problem of protecting sensitive information: disconnect USB ports, the absence of DVD burners, although the monitor screen can be photographed using a mobile phone.
  Questions:
  
  1. Is this viable computer management model viable? What are the pitfalls?
     What server characteristics are important, and what should they be?
     How expensive is it compared to the common model of managing an IT economy?
     Who provides such solutions in the Kazakh or Russian market?
     Where did they implement such a solution so that they could be viewed and viewed in action?
     What are the alternatives to effective management? Need to get familiar with ITIL?
     PS Question about the OS that will be used on terminals and servers below.
     Employees, as they perform their work duties, need to install additional software, such as dictionaries, translators, graphic editors, etc. Sometimes it is necessary to install the software one-time - worked for a couple of days, and then took it down. Taking into account the Law on the Protection of Copyright and Related Rights, the issue of using licensed software is in the first place, all the same, we are law-abiding citizens of our country, or at least we want to be, first. Secondly, government procurement of the necessary software can be delayed for several months (say thanks to the Law on Public Procurement). You can of course take into account a lot in the IT development strategy in the company and procure according to plan. But MUCH is not everything. Third, writing technical specifications for public procurement of finished software can lead one of the bidders to provide alternative software with a lower price that is not inferior to the software they were supposed to buy (let's say the second, thanks to the Public Procurement Law). This can lead to additional costs for employee training (again, the time factor). Or, somehow, to cheat with “tech-specs,” so as not to contradict the Law on CP. The solution to these problems I see in the use of Linux (Ubuntu, Mandriva, RedHat, SuSe, etc.) and open source software. But there are also many questions:
     
     1. How to deal with ready-made ICs and their “clients” developed under Windows OS?
        How compatible are OpenOffice documents with MS Office? Will the company's clients be able to open and correct documents typed in OpenOffice or vice versa? By the way, IBM also offers its office software, Symphony, free of charge, although only it is still damp.
        Who on the market offers OS technical support and open source software?
        And will all this “farm” with an open source GPL match? All the same, the software will be used for profit.
        
        These are the questions in my head, to which I myself am looking for answers, but have not yet found it. Maybe someone will clearly explain everything to me or throw off a link to a FRESH article on the web where there are answers so that there are fewer questions in my head. Although there may be others! THANK!