Quote: "Can I use these model packs in unity?"
Yes, with some work.
Quote: "how to convert them along with textures and/or animations?"
Try searching.
Quote: "Graphics in unity are cutting-edge, but in fpsc are low-resolution and null."
The resolution of FPSC games can be the same of any Unity game, however test games are fixed at 1024x768.
Quote: "No scripting required if you want in fpsc, but in unity you have to script (I have playmaker plugin for Unity for visual scripting )."
To make a good game in either engine will require some degree of scripting.
Quote: "But really the most important point which confuses me is the rapidity of development using fpsc, really you can make alot of playable stuff in MINUTES or few hours, so do you think that I should consider this point to the detriment of high quality graphics/professional gameplay in Unity?"
Even if you can make a game in minutes with FPSC, I'd still suggest taking your time and developing something worthwhile. This really isn't debatable, because the time spent developing a game in FPSC could be more than that of a Unity game. It varies by developer, of course.
Quote: "Thanks and I hope that all members would participate"
Good luck there...