This is all fine for gravitation, but not for 'real' forces. 
The electromagnetic force for example remains a force,
and it causes accelerations satisfying F = ma.
(Avoiding non-flat complications, and with F and a 4-vectors)
As for the weak interaction, of course it produces real forces too.
It doesn't matter whether electrons scatter elastically
through exchange of a virtual photon or a virtual Z-boson.
In both cases their momentum is changed,
so a real force must have acted somewhere in between.
For the rest, the use of 'force' is just folklore,
like in the never-ending discussions about a 'fifth force',
which is really a fifth interaction.
 Unless you linearise, invent gravitons,
and start exchanging those in the by now flat spacetime.
No experience with actually doing it,
beyond the lowest order divergencies are known to be nasty.