Securame

You need Internet Explorer, indeed.

No

You started a tour. No mouse? Plug another monitor (so you have both VGA and HDMI). Or just access the device from a computer (Internet Explorer or SmartPSS) and reset it to default.

You need DS-7608NI-E2/A. If they sent you the wrong unit, just send it back.

It is disabled by default now on current firmwares, and has been disabled for a long time. But it used to be ON by default a few years back.

https://www.dahuasecurity.com/support/downloadCenter/softwares?id=2&child=272

Disable UPnP on the Hikvision camera (in fact, disable it everywhere).

iVMS-4200 Lite https://www.hikvision.com/europe/Support/Downloads/Client-Software

If that is the case, the problem should be related to your network connection/networking, and not the firmware.

They must be Hikvision OEMs.

iVMS-4200 is only for Hikivision devices. It will not work with this IP camera.

I am quite sure it is not ONE, mbut TWO IP cameras, up to 6MP. You can keep your existing 4 HDTVI cameras, and add 2 Hikvision IP cameras (up to 6MP). You might also be able to add ONVIF cameras, but I would go for Hikvision cameras just to be on the safe side.

It could also be aliens.

For PSS you have to use Dahua units, either Dahua or any of their rebranded units/OEMs.

I can't be of any help here, but can you post the URLs you use to playback recorded files with RTSP? Thanks!