No, emulators are not dangerous. Emulators just help you to play games on your computer. They don't do any harm to your computer at all.
Emulator are legeal if you have that gaming console and the game you are playing but illegeal if you dont have those
It depends on where you download them. If you want game emulators, go to www.emulator-zone.com. They review a lot of emulators and they are all safe.
Downloading with 100% safety is not possible but the Emulator-Zone is a good place.
There are no PS3 emulators and the bios file for the PS3 would not work in a PS2 emulator
Yes. Various emulators support emulating linking between two consoles. VBALink and NO$GBA support linking Game Boy Advance games, and BGB and TGB support linking Game Boy / Game Boy Color games.
It is possible to use a PlayStation 2 emulator to play PS2 games on your computer. It is only legal to do if you own an original copy of the game.
Dangerous ones
No, you cannot get Nintendo events for emulators. The emulators do not have the feature to connect by link or by Wi-Fi.
You cannot put emulators on the DS itself, but you have to install them on your PC.
Instead of running the original (because they no longer exist , are too expensive or hard to get or dangerous or...) You emulate and run on a different platform that you can afford (can get a hold of, can crash and recover from, ...).
The android market has a number of good emulators, including fpse (playstation). The slide.me market has all the -droid emulators (gearoid, gameboid, psx4droid, etc.) There are some other emulators too, like a great N64 one by paulscode. You will need to google for this.
There are a number of Dreamcast emulators available for download for a PC. Some of the most popular emulators are Demul, MESS, nullDC, and SEGA Visual Simulator.
any DS emulators you can find
There are many sources of emulators, and one resource I can definitely recommend is known as Zophar's domain. There are many websites dedicated to emulations, and places to find emulators, the best step to take is to search Google for an emulator based on the system you are looking to emulate. It is imperative to exercise caution, though, as some viruses will masquerade as emulators, particularly as emulators for current systems.
emulators
well all emulators go into the game folder on your memory card if that's what your asking
You actually can't. Since those are emulators and not connected with eachother.
I believe there are emulators that you can use. https://www.androidauthority.com/best-android-emulators-for-pc-655308/
Yes.