Does that come with the .dll file I need?
Yes, it does. Fully automatic install.
Also is it normal that when pulling anything over 3 g's the aircraft will continue to pull for at least 3 seconds after the stick is released and suddenly disengage? or it this a problem that is fixed by the Hornet_FCS.dll as well?
No, that's not normal, and no, the v16.1 doesn't do that. The FCS always tries, barring any input from the pilot, to maintain 1 G loading on the plane. That does NOT mean it will level out automatically, but it will, when the stick is neutral, try to achieve a 1G load on the plane. So if you pull a 4G vertical pull up, when the stick is neutralized, the plane will wind up going straight up, but no longer pulling more than 1 G. So essentially straight and level, going straight up, if that makes sense. If you then do a 3 G push over long enough, then release the stick, you will level up again, see what I mean? If you go through turbulence of some kind, like Clear Air turb, or whatever, the plane will bounce around, but the FCS will try to keep the G loading to 1 G, so you'll see the elevaters trying to compensate for the turbulence, as it happens.
If you pull enough G to cause a blackout, just let go, or neutralize the stick, and you will come out of the blackout in a couple seconds. There are settings in the FSX.cfg file that affect this whole situation, but I've never messed with them.
Hope this helps
Pat☺