FMS streamed from public IP address

Thanks.

1. if i dont install the apache server bundled with the FMS, is it  okay? I dont intend to stream through port 80...

That's fine, you're going to say no during the installer.  Then if you want FMS to share port 80 with Apache you'll want to setup FMS to do HTTP Proxy in the configuration files and proxy to the port your Apache listens on directly (which you'll want to add).  If you don't care about FMS on 80, then just make sure FMS doesn't listen there and you'll be fine.

2. what is the  difference between port 1935 and 19350? I saw 2 files in the FMS  directory, namely fms.ini and Adaptor.xml

19350 is a minor technicality that FMS uses to communicate between its processes.  You can ignore it for the most part as a control channel.

in fms.ini it binds to  1935, but in adaptor.xml it binds to 19350...

3. in adaptor.xml  there one value like this:

<HostPort name="edge1"  ctl_channel="localhost:19350">${ADAPTOR.HOSTPORT}</HostPort>

there's  an explanation in above it that it binds to some ip we configure here,  but if you wanna bind to any ip then omit the localhost and leave it  like ":19350" my question is that is this necessary to do so in order  for people outside our network to connect the development PC ?

Well, yes - in that if you leave this empty FMS will bind to port 1935 on all IPs your system has.  If you list them specifically then we'll only listen on the IPs specified, if you list only localhost then those who come through a different IP than the 127.0.0.1 loopback interface won't be able to connect.

4.  about security at the proxy server or ISP, I've confirmed with my boss  that he's opened the port 1935 to be allowed, and he's also confirmed  with the ISP that they dont block port 1935..

Great.