For siemens packages you can use WinCC, which is OPC compliant, and object based. Or a cheaper option on Siemens side is Protool Pro RT. This has some goochy utilities, like recipe handling/report handling etc.
But there would be cheaper options. You can get MPI to Ethernet converters, plug into a generic opc onto a PC, and use any cheapy SCADA you like as long as they are opc compliant.
Yes you can change the language, in Project manager Options/Customize/manage Texts. From there select 'change language' to see if any other were configured for the project. But If your project comments are written in one language, then you will have to manually edit them. Or you could export them and use a program to do this.