1:
40x40x20 means....40 in the width & length...and 20 in the height.
It isnt possible to expand...
And yes it uses a loading screen to switch from levels...
50 is the maximum.
2:
I hate coding and scripting...
Well FPSC is like "made for me"...
So i guess you would like this as much as i do...
(of course it uses scripting but! Even i can make/edit scripts on here)
3:
Hmmm actually dont know, you should check the site...
4:
With some mods you can do almost anything with it...
But than the problem is, that you would have to code...
As for NPC's talking to you, is already done...so yes!
And as for how interactive? Depends...do you want it to be interactive?
Because Butters made a video of his level which was very interactive...
Again, this isnt FPSC...but this would be your animating skills
and "scripting"....
I am doing these " " because i personally dont see this like
scripting....cause its so easy!
Mission and objectives...uhm yeah..
You can do this by triggerzones...
so it will show up a hud...which says: (for example)
"Kill the marine on the other side of the room!"
After you killed the marine you should put something in the destroy script..and it would say:
"Well done soldier! - Objective: 01, completed!"
Etc...etc..
its really easy to use...and i would recommend this if you hate coding and such...
But if you are still wondering...
than check some youtube vids...and some other threads...