  Cosmological parameters can be measured by comparing peculiar velocities with
those predicted from a galaxy density field. Previous work has tested the
accuracy of this approach with N-body simulations, but generally on idealised
mock galaxy surveys. However, systematic biases may arise solely due to survey
selection effects such as flux-limited samples, edge-effects, and complications
due to the obscuration of the Galactic plane. In this work, we explore the
impact of each of these effects individually well as collectively, using the
semi-analytic models from numerical simulations to generate mock catalogues
that mimic the 2M++ density field. We find the reconstruction and analysis
methods used for our 2M++ mocks produce a value of fsigma_8 that is biased high
by a factor 1.04 \pm 0.01 compared to the true value. Moreover, a cosmic volume
matching that of 2M++ has a cosmic variance uncertainty in fsigma_8 of ~5%. The
systematic bias is a function of distance: it is unbiased close to the origin
but is biased slightly high for distances in the range 100-180 Mpc/h.
Correcting for this small bias, we find the linear fsigma_8 = 0.362 \pm 0.023.
The predicted peculiar velocities from 2M++ have an error of 170 km/s that
slowly increases with distance, exceeding 200 km/s only at distances of 180-200
Mpc/h. Finally, the residual bulk flow speeds found in previous work are shown
to be not in conflict with those expected in the Lambda cold dark matter model.
