I think that what you are looking for is not exactly called recorder. If what you want is live streaming you will need an encoder module. Same function than FMLE.
If you can not ask user to install FMLE you need same function embeded in the webpage.
- and 2.- Usually this has been done with a flash plugin. There are samples in internet of that module. But this will not work in mobiles and with Flash being phased out soon it will not work in desktop browsers either.
If you target is mobile, check Wowza GoCoder, you have an SDK to create native applications and you also have a simple application that is ready to use (but user need to install it)
Since recently we have WebRTC technologies to use the webcam in the browser. (Wihtout depending of external plugins, or applications) Wowza already support an webRTC input. This seems to be the way for the future, but this is quite new and only will work in the latest browsers but it should work in desktop and in mobiles.
WebRTC samples:
https://webrtc.github.io/samples/
3- You do not need the FMLE in this scenario. End users is doing the encoding.
4- In Wowza configure you can set that all the streams in an application being recorded automatically. You can also have an http API to start/stop the recording at any moment, if you want fine control.
5- It will depend of your usage. This is is sometging you need evaluate,
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…