Sylvain writes:

for one thing you won't be able to taxi, except in
circles ...

That isn't quite true. If you start out _very_ slowly, you could
conceivably hold the aircraft in line until aerodynamic forces make
the rudder effective (prop wash over the rudder can help, too).

... then even if you could line up with the
runway, you won't be able to keep the thing straight,
because the wheels will be able to counteract
the aymetry, and the control surfaces won't be
producing enough aerodynamic force to keep the
thing straight ...

Here again, with a long-enough runway and a very gentle start, you
might be able to build up enough speed to take off.

... the Baron in MS FS has none of these
problems, and is thus not very realistic...

I just tried it, and it has all these problems. An attempt to taxi
sends the aircraft in circles unless you start out very gently indeed.
I can't find a runway long enough to allow me to reach any kind of
rotation speed on one engine, but I did get as high as 62 knots (and
only that high because MSFS allows me to roll over grass and other
flat surfaces at the airport without necessarily crashing, although
the Dreamfleet Baron doesn't have an unlimited tolerance for bouncing
around, I think).

The excellent Dreamfleet Baron model is more realistic than the
default MSFS Baron, but they both display the behavior you mention. I
was unable to taxi or take off with either of them on only one engine.
Try it and see.

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