yes they are but it looks better with p-mags
No the mk 16 uses mags that are = to m4 - m16 mags. It looks like the mk17's mag is more like an M-14 but I cannot confirm that m14 mags will fit a mk17.
m4 there are spare parts
One would be able to find out more information about m4 airsoft guns online on Amazon. Two other sites that have some information about m4 airsoft guns are wikiHow and HobbyTron.
The M4 CARBINE IS BETTER THAN THE M16.
Most airsoft battles take place in close quarters which is what the m4 was made for. Unlike the m16 which was made for longer ranges
yes
Yes.
It all depends of the company making it. A Tokyo Marui M1A1 Thompson would be better than a cheap Wal-Mart M4. But a Classic Army M4 would be better than a CYMA M1A1 Thompson.
almost every gun for airsoft uses a 6mm (milimeter) BB. try that.
An M4 is a short barreled version of the M16, so yes, they can look quite similar.
The AK 47 Is Better Then m4